Crash, what kind of compressor do you have?Your compressor should have a regulator guage/ guages on it to keep the pressure between ,for instance 30psi to 50psi, depending on the air brush your using.
Some compressors have built in moisture traps to catch the condensation,especially, on warm days. If it doesn't have one you can buy an inline trap that fits on your airbrush hose between the compressor and airbrush. You need it so it won't spit out moisture to give an uneven spray.Hope that helps.
Alot of guys here no alot more then i do on the subject.