source.
For positioning -
1. Make a new skintone project of whatever your favourite skintone is. I use the SimCribbling ones. You can use whatever. Also make a new project for your piercings. I like to use blush for them instead of full-face makeup as you can put a thumbnail in that views in both the game and Body Shop (you can make thumbnails for full-face makeup, but it only shows in-game).
2. Open the adult female or adult male face texture from the skintone. This is for positioning purposes, so you can paint your piercings on the texture whereever you want them to appear. Make a new layer. Fill it with solid black. Call this layer Backdrop. Hide it for now.
3. Make a new layer. Call it Piercing.
4. Use a smallish brush (3-5 pixels) without much of a fuzzy edge, and paint a rough, flat version of your piercing in the area you want it, using about 30% grey for your colour.
5. Un-hide the Backdrop layer. Save what you have currently viewable, the flat grey piercing and the black background, as your texture.
6. Duplicate your Piercing layer, and hide the original Piercing layer. Name the new layer Piercing Alpha. Lock the transparency of the Piercing Alpha and fill it with white. Save what you have currently viewable, the white piercing and the black background, as your alpha.
7. Refresh the textures in Body Shop for your piercing project. The positioning and stretching on the piercing texture is probably going to be somewhat off.
8. Hide the Backdrop layer, delete the Piercing Alpha layer, and adjust the original grey Piercing layer to try to compensate for whatever distortion/incorrectness you may have.
9. Repeat steps 4-8 as needed until you have your piercing positioned correctly and as distortion-free as possible.
For texturing -
I personally found the easiest thing to do to get a decent shiny piercing texture was just to colour around the outside of the piercing texture. I locked the transparency so I couldn't colour outside the lines... Then painted around the edges with a big fuzzy brush at about 50-60% grey, then around the very edgiest edge again with a slightly smaller fuzzy brush at about 70-80% grey to give it a nice rounded look.
If you're using Photoshop, the use of Paths to do this makes it SO easy to get good shading around the edges really quick. If you're using Photoshop and not familiar with the use of Paths (which I wasn't for a long time and I thought I knew Photoshop pretty well), there's a GREAT tutorial on making realistic new eye textures in Photoshop here: http://www.kandsdesign.com/kim/eyemap-tut.html ... taught me a lot and has a lot of other good info too... just make sure you do it with the colours suggested the first time or you will be totally lost.
Anyway. Last thing to do is to use your little fuzzy brush with white to just add a smidge of highlight to a couple spots on your piercing, to create a bit of a shiny highlight.
If you find your shinyness is still looking a bit flat, best thing I can recommend is taking a look at the textures people have done previously to texture piercings and try to examine the way they've laid down the shading. You can also look at pictures of real piercings to get an idea of how their shading looks, too.
