Buy some older kits and practice on them before you build an expensive plastic or resin kit. This way if you make mistakes the cost of the kit won't be hitting you in the head. That comes from personal experience.
Depending on which type of airbrush you have (single or double action) open the nozzle so only a small amount of paint comes out of the brush. It's better to build up the paint job with small coats than it is to open the nozzle all the way and paint the kit in one try with a large blast of paint. Small amounts of paint will insure you don't cover up the small details and or parts.
Erik
"Don't fruit the beer."
Newest model buys:
More than I care to think about. It's time for a support group.