After I downloaded these icons, I saw several things which you could really improve on. First off, the reflection is too small. The reflection doesn't cover the full top of the flag, but leaves some pixels open. Also, the borders of the flags appear different sometimes. For example the border of the flag called NCYP looks correct, but the NETH flag has a totally different border as well as the NATO flag. I hope these tips gave you a little to improve on! Thanks for sharing.