Airframes
Benevolens Magister
Agree with Andy there. When first using an airbrush, there's a temptation to try to cover everything fully in one go. All this does is make the paint 'pool', which will then flow away from some areas, leaving 'thin' spots, and clog in others, leaving thick, uneven coverage. As Andy said, spray even, thin coats, letting each one dry before doing the next, and always keep the brush moving, in one direction. That way, you'll get a good, even, solid finish. Practice, practice, practice!