I heard about a nail art technique, "dragon skin", where you use a UV polish and cover it with soap foam before curing so it gets the shape of the bubbles fixed into it, then adding a shimmer powder

I have UV resin, so I tried to give an interesting asteroid texture to these blanks, which are filled with pink powder that shimmers gold and green. I used that same powder on top of the black UV resin

I really like it, I hope they look cool once they're in the number shells!