..Ufff, you guys aren't very helpful!
But, if you ask how to make a skin for Sakura, you're probably not skilled yet!!
It's pretty complicated to make a good skin, and believe me, I know what I'm saying..Your best shot would be getting one of the skins in raw format (not compiled in .skn file), and than modify segments/parts of skin at your will..but it will take you time and effort to do it right..
Programs that I use would be PhotoShop and Fireworks (NeoGunKuruma helped with that)..
If you'll have any more concrete questions, ask and we'll try to answer you..