I've been making icons for a while now and i made this tutorial for photoshop on how to make an icon using a base of toph from avatar.
This is pretty much how i make my icons. There is no method which i follow to make my icons. I just experiment, if there's something i don't like I just delete that layer. I start by adding one colour and set the layer to multiply or overlay or whatever looks good and changing the opacity. I like adding peaches and blues. Then comes adding different patterns to new layers. I look for patterns on deviantart, there are lots here. Finally comes the text or you can leave that out
The base i used was from avatarspirit.net.
All other patterns are credited in the tutorial.
Feel free to ask any questions.