This is something I've been intending to do with Ariel (my Sprite) for a long time, but I had some trouble finding something appropriately sized to use as studs. I ended up getting a sheet of self-adhesive rhinestones from the scrapbooking section at Michael's. I scraped off the existing adhesive with my nail and used some Elmer's white glue and Aleene's tacky glue to apply them. The rings in his ears are existing drilled piercings, the studs are the new glued ones. I'm really pleased with the result and I'm glad I finally sat down and did it. I had to re-glue a couple after the initial application, but after that they all held firm during a four-day anime con, which is a good test of durability, I think.
I did also sit down with some jewelry findings and tried to figure out a way to give him an industrial piercing in his right ear, but the shape of it just doesn't lend itself to that sort of thing without further modification so I went with the larger stud. That's the one I used the tacky glue on, it was just too heavy for the Elmer's. I intend to repaint him over the summer so this was basically a test run to see how much I liked the piercings, I'm definitely putting them all back on once he's got his new face.
Might give him a tattoo of some sort as well at some point, maybe wings on his back (I did always like the Harpy scene in The Tempest).