I just built a parts booth myself! I had it in my mind everytime I went to paint a small piece and overspray would get on the bench or floor and stay in the air and stink up the shop. It's basically a "fume hood" that is used in chemistry labs.
So, I made a 3'x2' box out of rigid foam insulation (pink or blue) and left the front open, but with a plastic sheet hanging down about 6-8". On top I cut a hole and inserted a furnace duct "amplifier" - it's a fan inside a piece of 4" duct and moves quite a bit of air, but gently. At the exit, I fashioned a box with a piece of allergen filter to catch the paint. As well, I put a heater inside and a thermometer. Being made of thermal foam, it heats up fast. So now, I hang or place parts in the box, turn on the fan and heater and paint away. Any overspray is contained and the exhausted paint doesn't smell!
I'll post a photo later.