The basic skills of airbrushing are:
~ learning to 'feather' the air control button to get fine, fine
mists of paint on up to heavy sprays.
~ keeping the air tip clean so that it won't splatter blobs of
ink on your work.
~ adjusting the overall airflow to achieve smooth, even coverage
on up to splattery, textured-looking coverage.
~ using liquid or peel-and-stick frisket to coat areas that must
not be sprayed. Some lovely designs result from spraying, then
removing a strip of frisket, spraying again, removing another
strip, spraying again. Each spraying can be a different color, or
sequentially-darkening effects of the same hue.