let me give you some advice about tattoo parties!
1) Wait until a few people have gone to judge the artist(s) (if it's not what you want, DON'T do it just cause it's free)
2) Don't wait too long or the artist may get drunk or very tired (seen weird things happen)
3) Follow standard procedures to ensure *safety* and hygeine (otherwise, decline tattoo)
I like the orb in the hand idea