If you're thinking about getting a tattoo and don't know where to start, Keith McCurdy's brain would be a good one to pick.

He's self-taught, started in his mom's Delaware kitchen with a starter kit he bought online when he was a teenager, and eventually moved to New York City to become "Bang Bang," a name synonymous with celebrity ink and owed to the double guns tattooed on his neck.

Now 29 years old, McCurdy has opened an eponymous shop in SoHo and tattooed Katy Perry, Adele and Cara Delevingne; he gave Justin Beiber a tattoo on a private jet in the sky, and Rihanna wrote in the forward to McCurdy's memoir, "I'm going to keep my skin pretty as long as possible, but the minute that starts to go south -- Bang Bang can just knock me out and I'll wake up a week later, covered in tattoos. Maybe when I'm fifty."