I have been using airbrush for almost 4 years now but I am yet to be able to achieve an evenly airbrushed cake.I am refering to some airbrushing work I have seen here that looks perfect like buttercream was used.I tried airbrushing in circular motions,up-and-down motions but nothing has produced an even work yet.My airbrushed cakes usually have patches where some parts are darker than the others,usually resulting in various shades of thesame color.I changed my powercat airbrush gadgets that I had thinking that was the problem,but results are still thesame.Any tips or/and instructions will be appriciated.

Well, after 4 years, I might be thinking the problem is the machine and not your technique. But...here is a website that I found pretty helpful in using mine.
http://www.howtoairbrush.com/

Even though the type of paint is different, some of the techniques are the same.

Thanks Malakin.I am going through the link you kindly suggested and getting my dummy ready as I speak.You have been helpful.

Thanks, I've been having problems too and was planning on changing my airbrush, what is it, pen? (sorry, I don't know the name) but I'm glad I didn't, I'll try this first and then decide if my airbrush machine sucks or I suck at it, hahaha I really hope it's the machine!!!