I don't have a strong opinion on tattoos, though personally I would not get one. If the artist uses excellent sanitation and procedures, so it's safe, then it's up to the individual's inclination and taste to have one. As long as the designs are not somehow offensive to society, it's a personal issue. I have admired some fantastic "body art" by really talented artists, but wonder how that work will hold up when the "living canvas" begins to sag. 
Some cultures require tattoos as a rite of passage, while others forbid them. It's a subjective issue. IMO,
Piercings, though, I dislike because anything that creates a permanent hole can be re-opened and infected by poor hygiene even if the person doing the piercing did a great job; once the "piercee" is on his or her own, things can go wrong. There have been horror stories about piercings gone bad. Again, however, some cultures consider piercing to be part of accepted and expected behavior. But for me, it's self mutilation in a way that can compromise health and wellbeing, so I'm kind of repulsed by it. I don't even like pierced ears even though that is a "natural" part of our culture. Oh well.