The Clow/Yuuko icon is gorgeous. ♥ I don't really have any suggestions on how to improve it, it looks great as it is to me. The Sakura icon is pretty too, but perhaps the flower petals dominate the pic a little bit too much? They are so bright, and make Sakura look slightly faded. That's probably just a matter of personal preference though, it's still very nice as it is.

Good luck with the job! :)