Painting parts requires a clean space and getting overspray on nearby items is always a problem. Having a dedicated place to paint that will adapt to any size part is very nice. Here's a paint booth I made in an afternoon using cheap supplies from Home Depot, and it doesn't require any fancy tools to make. I keep the booth in the back yard so it doesn't take up space in the garage, and it will fold up flat if needed. Another great thing about this design is that it keeps out dust pretty good while the part is drying. The booth has a sliding/removable shelf to accept both small parts, and larger parts that can be hung from the top bar. I've also included a lazy susan on the shelf to spin parts as I paint. This is SO much nicer than just spraying on a table in the garage.

Breathing
When you spray paint, don't breathe the fumes. If you can smell it, you're breathing it. Don't rely on those little paper masks either, they do nothing. Use a decent respirator with filters. They're about $30 at Home Depot. You'll look like a dork, but your airway and brain cells will thank you!

Seeing
If you value your eyes as much as your airway and brain cells, consider using eye protection too. Paint flies everywhere. This is especially important if you wear contacts, and it will add to the dork-effect quite nicely.