Or a really narrow exacto knife.
The blade is narrow, sharp(ish) and thin, and it's good for getting into tight places, tucking glass back where it is supposed to be, and helping with sculptural shaping.
It's hard to show you what it does, because it's the sort of thing that you use to tidy up and clean up and shape, not really to make textures.
Well - actually - I can. I used it on this eye to make the texture. I think of it as the "Cactus Dragon Eye."