Alright, I've been thinking about making a tutorial for some time now. I tried to explain this as thoroughly as possible, and if anyone has any suggestions for improvement, or wants to point out that I was an idiot and forgot a part, please PM me and I'll update it.
Remember, this is a tutorial - try not doing it exactly as I show it, but vary and carry on the techniques when you make new sigs.
http://img441.imageshack.us/img441/4...designsgl0.png
And one last thing - save this as a PNG file, so you don't lose your transparency.
I know this is really basic, but I hope it will find an audience anyway.
-konfusion