You just did?

Seems to me you’re pretty far along with determining what you want - an HO scale 10’x20’ layout with capacity for 25-30 cars representing a branch line for one and maybe two operators.  And you have mentioned some well known layouts that appeal to you.  I assume from your mention of those three railroads that you’re interested in a longer point to point, not a continuous running loop.

Sounds like you’re off to a pretty good start.

There aren’t that many ways you can fit benchwork for a point to point into a 10’x20’ area that presumably has a door or two and still leave generous aisle space.  Sketch those out.  Pencil a bit of track in with staging at one end.

If you’re not sure exactly what you want, try some experiments.  It would probably be pretty easy to build a shelf down the length of a 20’ wall (assuming you have one with no doors) and tack down track temporarily to try a few different things.  Put a couple tracks at one end for staging, a runaround in the middle, and scatter a few industrial sidings around.  See if you like switching that sort of thing.  If you do, stretch that idea out around the room and fill in some more details.  If you don’t, well, try something else.

Go out and see/operate other layouts......

It's hard when it's all abstract. Forums and videos are nice but there is no substitute for time in the seat.  There are all kinds of local regional and national train events to attend where operations are part of it.  Eben if you don't think you are an operations type it still exposes you to different kinds things and see what works for you

Maybe there are some MRH folks near you you can hook up with or join the OPSIG group for the cheap and see the call board they over there that works for you.  http://www.opsig.org/

Disposable layout

Since your desires haven't really gelled, I would suggest building a layout but be aware that it might be a stepping stone to what you really want.  

A 10x 20 space will allow a "doughnut" with 24" wide benches around the edges and  a break someplace to get into the middle.  The alternative would be a G shaped layout with 16" wide benches and 3 ft aisles.  

Pick a benchwork footprint and build the benchwork as "open grid" style.  On a couple sections build some "permanent' switching areas and assume that the rest of the layout, everything above the benchwork might not survive the time it takes you to figure out what you want.  Keep the design really simple.  Two, maybe three switching areas with 2-3 spurs, a yard with a runaround and a couple yard tracks, maybe an engine tie up track, maybe an interchange.

Post a plan for comments.

Keep the wiring simple and the track plan simple.  Then run it and see what you like.  You may love the plan and never change it.  You might decide its not what you want at all.  If its not right, you might want to rebuild it to what you do want.

I have had 4 layouts in the last 25-30 years, which includes a 10 year stretch where I wasn't modeling at all.  I have changed the road I model from my freelance, club freelance, PRR, PC, LV, RDG 1974, MP 1965, RDG 1968 freelance, RDG 1952 based on a prototype, P&R 1903 based on a prototype, to bigger 1903 based on a prototype.  There were also a couple swings through N scale and HOn3 mixed in there too.  The PRR/PC seemed too "big", the LV wasn't hauling any coal in the era I wanted and there weren't good Alco engines when I was modeling it, I was working for the MP so modeling it was just a bit too close, I freelanced a RDG branch and decided I wanted to model a prototype, found the prototype, then figured out I liked smaller steam, backdated to 1900-1905, then moved.

Nothing wrong with building

Nothing wrong with building stepping stone layouts.  I designed and built my first layout in college in my garage, a 16x19' hollow L with a yard, single track mainline, siding and tear drop return loops at both ends.  I've built two other layouts since.  None were my dream layout but I enjoyed the process of building, got to run a little and learned stuff along the way.  You can build a layout and tear it down and build another.  Thats a normal thing in the hobby.  And it's better than building nothing and just wishing.

It takes awhile sometimes.

I built several small/ medium sized layouts around the modern prototypes near me. Amtrak and NS. NS trains around here mostly run off  hours because the former PRR mainlines are now owned by Amtrak. I got bored when I realized how rarely trains actually run through Lancaster county. 
 

I built a layout based on the R&N railroad but got bored with it too. I don’t know the area it runs through very well or the actual track layout and scenery. 
 

I wanted something local so I made up a railroad based on the history of several successful short lines (A&R, G&W). I modeled modern Nscale at the time and my railroad was the Lancaster and Reading. 
I wanted my railroad to be centered on Lancaster city which to me means a yard to for locals to work out of. 
I had a decent sized yard that was well designed ( runaround track, separate yard lead, etc.). 
At first I enjoyed operating all the different things.
Eventually I filled every extra space in the room with more yard or industrial trackage. I had 4 staging tracks that could hold about 200 cars total.
I could have kept a dispatcher, yard master, 2 road crews and 2-3 local crews busy. In a 9’x11’ room. I realized that I had ‘everything’ but I couldn’t do justice to any single thing. 
 

I went back to the drawing board when I switched to HO scale. Now I focused on the minimum I needed for operation using a small basic yard, a few industries and a branch line. I wanted a continuous run for the mainline. Cars actually go somewhere and come from somewhere (staging). 
 

My current version is a refinement of that basic concept and I simplified the trackage even more. I am starting with what I consider to be the key section, the yard. Most of the visible trackage and turnouts are on this section between the yard and the largest industry in Lancaster county at the time, Armstrong Cork plant. 
 

I plan to make the village module fairly simple like the prototype (there was one siding serving a tobacco warehouse and a coal dealer) with the addition of a branch that comes off and goes into staging. 
I actually model more the junctions in the middle of freight traffic than the beginning or destination. I like sorting cars and the interchange between trains. 
 

I did find that there was a prototype for the railroad I imagined and I stole some of its 100 year history. 
 

I would suggest building in sections like the TOMA concept that you can expand. 

deciding what you want in a layout?

  I think it should start at the start. What got you interested in railroads and trains originally? Was it childhood memories of local trains or maybe Christmas tree toy trains, etc.   If you don't have a basic desire for something then why build anything? A hobby should be enjoyable not a task to complete.....DaveB

Vood ideas here

Been there

I can very much relate to the feelings you describe John.  For probably close to 10 years, my hobby was little more than sketching layout plans and building concept railroads.  Operating locally definitely helped to expose me to a number of layouts and see the type of work I enjoyed most (yard and local switching), but looking back, didn't really assist with narrowing down my options regarding various layout concepts.  All layouts I saw nearby were based on busy mainlines of one sort or another, so that's the path I originally started down.

It wasn't until I got more involved with railfanning that I realized I actually preferred the slower, simpler pace of a regional railroad.  Following along as their locals and yard jobs switched was just the the thing for me, and has proven to be a layout concept that's held my attention and interest for 20 years of enjoyable modeling and operations.

Even if you're not interested in modern railroading, or in the railroads near you, is there a type of operation you gravitate toward when you railfan, such as yard switching, local switching, mainline running, etc.?  Is the equipment you've gathered so far related to a particular prototype and/or era?

...

Lots of good advice here.  You don’t say where you are, but I think Steve K’s advice to go to local shows, hobby shops (if there are any in your area...they’re getting pretty scarce these days), and trying to connect with local modeler with layouts will be the most helpful.  The best way to identify your likes and dislikes is to try operating at more layouts and see and talk to other layout owners.  Most layout owners are happy to show off their railroad, all you have to do is ask.

comfortable workspace?

You say you have a 10'x20' space in the garage. Is it ready for a layout? Is it a place where you would enjoy spending long stretches of time building one?

I don't know whether this applies to you or not, but in case it does (or someone else reading this thread) if your designated layout space is cluttered with other junk, or poorly lit, or cold, or dusty, or just unappealing in some other way, your subconscious will always steer you back to the armchair convinced you have more planning and research to do.

On the other hand, if your designated layout space is a place where you would enjoy spending time, you'll be that much more inclined to go out there and start putting some benchwork together even if it's just to set up a temporary loop of track.

Once you do that, you'll become more opinionated about your "givens and druthers" and planning for the "permanent" layout (if there is such a thing) will become more focused.

A great article worthy of your time.....

Lance M. put this out not too long ago.  As always he is spot on with it

https://www.shelflayouts.com/post/large-space-small-skills

And another quick read for you from him

https://www.shelflayouts.com/post/picking-a-theme-setting-your-scope

Never had that problem.  I

Never had that problem.  I don't get it?  I have seen many, here, and on other forums, suffer from analysis paralysis, for most, it drags on, to endless post, and streams of pictures, looking for justification.

Good luck.

Mike.

I have seen many, here, and

I never could get that.  It's like some need approval from other hobbyists.  Much of it is common sense and most people learn best through "doing" and trial and error.  My biggest problem was having space and stability as I was moving a lot in my earlier years. But heck, when was in grad school in college, I managed to get a good sized layout up in my garage - just didn't have time to get much scenery going before I was done with my masters degree and had to move for a new job.

Anyway, as the Nike commercial said "JUST DO IT!"

Analysis paralysis

As someone who occasionally has that problem I can tell you it’s not that.  It’s that before you start building, the possibilities are limitless.  Every step you take in the process of actually building something reduces your options, until you end up with a single actual layout.  So you want to make sure you pick the best option at every step.  It is the problem for which the saying “Don’t let the perfect be the enemy of the good” was coined.  Which, by the way, is excellent advice.

Deciding

Make a list of every thing you want and then put a numerical priority number next to it.

large city----1

small town----5

junction in the country----3

And keep going like that. How much space do you want between scenes will give you an idea of how many items on your wish list you can include. If you are one of those people who want everything on that list and can't seem to exclude some, switch scales to N or even Z.

One of the biggest blocks is seeing all the different stuff that other folks have done and wanting to do something similar and again you want to do it all. Building a model railroad is like buying a house. Unless you have a couple million to buy whatever house you want you have to make some choices on rooms, size, location ect.

Jack

Tabletop layout

Build a tabletop layout 5'4" x 12' (have the local lumber/hardware store like Lowes, Home Depot, etc. cut 2 sheets of plywood at the 5'4" mark - the 4 pieces will make the tabletop on a grid built to 5'4" x 12').  Note: fasten everything with screws.

Buy a bunch of Atlas sectional track.

Arrange the track on the tabletop and run some trains. Do some switching.  Note: fasten nothing permanently.

Change the track around, run some more trains.

Do this until you have an idea of what you like.  Then go from there with the tabletop or reuse the lumber for something bigger in your space.

Good luck

Paul

Analysis Paralysis vs. Age

I feel much the same way that John does and I think analysis paralysis increases with age since we see the future as more limited than when we were say college age.  We strive to move forward with as few regrets as possible but at the same time if you don't move forward you still have regrets.  A younger person can take this in stride but once you starting having health problems even if they are minor it impacts your life negatively.  From my own personal view I would love to find someone who likes to build benchwork but I would never fill the basement with it because I've seen too many "plywood pacifics" that had to later be torn out.

The point that Chris makes above is very important since my basement is NOT a comfortable work space so that needs to be addressed and then of course we get into budgeting issues in solving that problem.

Robert

I'm a little bit surprised that no one has mentioned TOMA.

With TOMA, you build a 2x4 or even 2x8 switching scene, with a simple return loop at each end.  If you are not sure what you want to model specifically, run it as a "plywood central" to see if you like what you built.  Without scenery, maybe some shoe boxes to represent industries, you can change it if you don't like something.  Once you are satisfied with what you built in the first section, make the track permanent, finish the scenery, and go on to build another TOMA section repeat until you have a finished layout.

Thanks everyone

I appreciate the comments from everyone. Given many of the comments I am pretty sure of what I am after. I think the biggest hurdle I've had is how to operate a layout and would solo operations be enough. I can say that I have decided that I want to operate with others, but leave my self the opportunity to operate the layout solo if needed. This is pushing me to a small branch line railroad with perhaps a small branch off of that to another switching area.

I've been looking at the blogs of others and have come to realize that I think what I like the best about a layout is scenery. A small branch line with a handful of customers over the length of the railroad allows a solo operator as well as an engineer/conductor type of operations. Fed from stub-ended staging it is a simply matter to just build the railroad without a lot of undue complexity. Trevor Marshall's Port Rowan in S scale exemplifies this soft of small railroad, with a high scenery to railroad mix. He can run with others, or run solo as needed without much issue at all.

So I think that settles it for me. I have 12' x 20' space ready for bench work (2' wide shelf along the outside of the space). I can have a decently long mainline (about 54') and a secondary branch off the main to a small switching are on a peninsula. I am going to focus my design efforts on the whole layout, while focusing construction on the outer shelf. I have a 2'x10' shelf layout at work that I will do the peninsula on so I can work on part of the railroad over lunch and the remainder at home. Should make for relatively decent progress I am hoping. Again, thanks for all the feedback thus far.

John

12x20 space

I have had two different layouts in 12x24 spaces.  One had 30" deep benchwork (leaves a 7 ft wide area in the middle of the room) and the other had 18" deep benchwork.  With 18" benchwork it allows a peninsula down the middle of the room and 3 ft aisles.  You do lose 25% of your layout surface in each scene, but you do gain a longer run and the opportunity for more scenes.