Girls with random tattoos all over their bodies that mean nothing but a need for them to 'feel cool' are idiots..
I wouldn't go that far, but too many go with the scrap book approach instead of something really cool and interesting with a focused them.
Themetic Tattoo principles require a vision and communicate that theme to those that see them. Maybe its a nature nymph theme, maybe its wild cat theme, mural or somethings else imagative vision. When done right super hot.
Scrap book tattoo principle is where someone treats they're body like a scrap book, each tattoo somethings only they understand and all together form no cohertant theme, its just abunch of meaningless (at least to most other people) body graffiti. In small doses it doesn't hurt someones sex appeal, but in extreme cases it ends up looking like their arm or body is rotting off.
Pierced Nipples on the other hand are really fucking hot to me.