I'm cheap too.

Or I like to think so. I have a spray booth on the first floor of my house, so I did spend quite a bit ($90) on a quiet fan. I created and printed a funnel to mount to the side of a plastic storage bin, and it's been successful ever since. I have all the basics covered, except lights. And, because it's a plastic bin, I can close the lid 95% of the way to draw air through even faster while I'm not painting.

I use rattle cans on occassion

So the fan is nice. 

Yes to boxes

For several years I used a moving box (well, several in succession...) as a paint booth.  No fan, but if I had to spray solvent-based paint I set the box up on the deck, and in the winter put it right outside the door so I could sit (almost) inside and paint.  I finally did build a paint booth, but the boxes worked fine until I could build one.

Paint box OK, but ...

... think safety.  One acquaintance, a PhD in Industrial Safety, told me to always wear a mask when spraying acrylics.  Just a surgical filter mask like those so common today was all that was needed.

My paint box, an old carton with the top and front cut off, lasted several decades until my wife gifted me a portable paint booth a couple of years ago.

I recently purchased a paint booth

I’ve avoided it for years. Instead I’ve used boxes, or just shoot acrylics right on my main work table and scrub it off later. Ive sprayed in the garage several times and never come out with good paint jobs there. Primarily because the air is too dusty and the climate is either too hot or to cold. 

When I recently decided to paint a locomotive with solvent paints and decided it was a good idea to buy a paint booth. Especially since they can be had for so cheap (I got mine for $200). I’ve placed my compressor and the paint booth on the same rolling cart and now have a dedicated painting station that I use practically every day. It’s great to be able to turn the fan on spray and let it vent for a short time then shut it off, no dust cloud of paint contaminating everything in the room. It’s also great to have the lighting. The turntable is sometimes useful also.

Something for your consideration.

Paint has a solvent.  It might be water or an organic chemical.  These have for the most part been tested for negative biological effects.  The colors or pigments most likely have not been tested.  Back not too long ago cadmium and chromium were used as pigments.  They were very bad health wise.  Are you going to take a chance that someday in the future we find that one or more of the organic pigments in paint is a strong carcinogen at very low levels of concentration when inhaled.  Your choice…..

Cardboard box plus

Hi,

fancy booth or not... I try to spray outside as much as possible, but even then, the use of a cardboard box has proven useful.

With the use of acrylics I'm not overly concerned about fumes, but it is nice to capture the overspray.

What I've found, when I used a too-small box I had particles of paint "bouncing" off the rear of the box. It created a "dusty" layer on the model which I didn't have otherwise.

Recently I aquired a slightly used air filter. I'm hoping to put that in my cardboard box soon. Even without the fan, I hope the filter will "catch" some overspray and prevent it from "bouncing" back on to my model. I may mount a fan if I feel fancy...

Depending on the paint in use, more efficient extraction and filtration may be necessary. Same thing for spraying indoors - but then I assume everyone on this forum is still in possession of good old "common sense"

Have fun!

I've never used anything but

I've never used anything but a cardboard box  inside  window , You DO need a fan to pull the excess outside , otherwise it blows back , its got no place to go but out . You can get  12 V dc brushless  fans cheap , I have one from an old defunct computer power supply. You can cut an a/c filter to stick below the fan to help diffuse the air across the entire chamber.

you also use Bernoulli effect if you want to try to avoid the filters.

In my opinion its easier to use a cardboard box , when your done using it you've some place to put your air brush / power supply and paint.

if you use one don't cut the flaps off , use them to seal the box in the window.

if you want to build one you can go to the recycling / dump or try habitat for humanity and pick up an old vent hood and replace the fan just use sheet flashing to make the box.