I actually use GIMP as my image editor of choice, although Adultery keeps trying to drag me over to the dark side known as Adobe. Google has been my best friend so far as finding decent scripts, patterns, and overlays for my theming needs. I usually save my stuff twice - once as an .xcf file (The GIMP equivalent of a .psd) and .psd file). I like the use of patterns and overlays (what's the difference - patterns are usually laid atop something whereas an overlay resides on top - HOWEVER, if you are using .xcf or .psd and depending on the transparency of the layer containing the pattern, you can make an overlay a pattern and a pattern an overlay! That would not be bad, however, when I think of Rassilon, my thoughts go more to Gallifrey and less with the tardis. I believe I did use the tardis - brakes on - for one of my earlier themes starts.