I have a single hole in each ear lobe, and a nose piercing.
I got my ears pierced as a child, and throughout my childhood/adolescence I went through phases where I'd be all about wearing earrings, and other phases where I couldn't be bothered. I don't think I ever stopped wearing earrings entirely, but there are stretches of time when I don't care as much and just wear the same pair of studs every day.
These days, earrings are an integral part of my outfit, even on weekends. I tend to go for "easy" earrings when I'm not dressed up (silver hoops, simple studs), but I always wear them and they are always a conscious choice. I like jewelry.
I got my nose pierced when I was a freshman in college, so I've had it for almost 10 years now. I originally decided upon it because a) I like my nose, b) I want to highlight my nose, and c) my nose isn't going to change shape or get saggy so it's a great place for a piercing. Given that that was my train of thought, and that I only really thought about getting the piercing for a few months before I sort of impulsively went and did it, I'm a little surprised that I love it as much as I do.
But in the end, I do
like my nose, my piercing is exceedingly well-placed (I did at least take the time to search out a really good piercing studio), and it's subtle. I've been wearing the same stud (silver with a clear crystal) for a few years now. I used to change it out every so often, but I've gone back to the one I got with the piercing because it's a slightly thicker gauge than what I've seen for sale, it goes with everything, and changing out a nose screw is a colossal pain in the, well, nose. It takes me a lot of time and wiggling and a bit of discomfort to manage it, so I remove my nose stud as infrequently as possible.
I've sort of thought about getting a tattoo, but in the end, I don't handle pain especially well. And there's nothing I can think of that I'd want on me, and nowhere I'd want to put it. Plus, even though I do admire some tattoos on other people, I see far too many that just don't look attractive to me at all. Chances are good I'd end up disliking anything I got. And unlike a piercing, you can't just stop wearing a tattoo, nor can you change the design as easily as you can change out a nose stud or a pair of earrings.