I've never noticed a tattoo&badboy correlation...Actually the super tatted up guys I know are really nice. It's the attitude more than the clothes. Egotistical, smooth talkers seem to be the worst I've come across. I listen closely when guys talk to try and pick up on the little stuff, and I observe how they interact with others (guy/girl friends or new acquaintances). How they treat others is a good way to tell if they're putting on a nice face for you.
Tattoos and piercings. Normally in black. He never gives two sh*ts about anything and can normally hold his own weight in fight, so an in shape guys. He will show off his arms and tattoos but in a way that does not look like he is trying at all.