Top textures tutorial
I forgot to add this in the vid..download it, put it into your top folder and open it and let it work..do this before editing any textures...
http://adf.ly/5srWP
I hope you understand the guide...
It is all about your photoshop skills and imagination ;)
You should also search for other photoshop guides...they do help a lot :)
Good luck
Important note: the tool was made by kamis1232 so credits to him for it