I've seen kits for sponge nail art from Konad, I assume they use "special" sponges but I don't own any so I tried it with a make up sponge wedge, just the regular ones you buy at the supermarket.
I did the base with China Glaze Rodeo Fanatic and the sponge part with China Glaze For Audrey. I added a silver stamp to make it all come together.
If you have any questions about this design let me know. Hope you like it!
BTW: I used scotch tape to divide the part of my nail where I didn't want the sponge color.