i airbrushed a 1/48th scale F-16. i painted it but there were some parts that werent so well done. i tried hand painting it with brushes but all of them left little marks; the marks look like almost scratches of paint taking off with a thin base layer still on. can you guys tell me what im doing wrong? what kind of paint brushes or should i not use them at all and just always use the airbrush?