As Mike Czech has told me sooo many times.....patience and practice.

You can practice on old 2L pop bottles and scrap plastic. Plasticing on paper doesn't give the same feel as plastic because the paint moves around more on plastic when you spray it, causing splatters and runs, which you don't want. Experiment with tip/needle sizes, paint thinning, and air pressures to get the results you want.

That is everything I know about the subject, except...clean it well before you put it away. And wear a respirator. You only get 2 lungs, and you need those to last you for a long time.