Thanks. For the tatoos I used a fine brush (3/0) and thin paint and a lot of patience. The trick is to seal the finished paintjob with clear flat laquer BEFORE applying the tatoos. This way you can always clean up the tatoos with some airbrush cleaner (the soapy one without any hard solvents) and a cotton swap, if you misspaint the tatoo, and the skinpaint underneath stays unharmed!
Cheers :D