I have found it also helps to wet down the floor of wherever you're working...keeps the dust down.

Also, I don't know how much background research you've done, but the key to a good finish (aside from avoiding contamination and using products that are compatible) is applying multiple light coats. One coat should not provide coverage. Depending on the colour, take the time and do at least 3+ coats.

EDIT: I'm not sure if you're going acrylic enamel (baaad idea- the finish won't last- I've tried it) or base/clear or what; but don't wait too long between coats (or before applying clear) because this just gives more time for something to contaminate your finish.

I'm also not clear on what type of paint you're using. I only have experience with automotive paint (expensive). If this is what you're using, it might end up costing the same amount to take it to be professionaly done or even powdercoated. Not sure about prices in America, but here in Canada you'd be looking at at least (although this depends on the type of paint) $100 for primer/base/clear plus it sounds like you're buying a gun of some sort. Unless you really want this to be DIY you might be better off getting it powdercoated (more durable too).