I've only ever used the template so I know how my banner will look on every device. This way no-one sees anything I didn't intend them to.No I used Gimp 2.8 to make my banner. I setup boundaries for all of the major zones and used them to setup my channel art. The areas outside my boundary have a texture to them but I'm not sure that I'm totally happy with it.
Thats a pretty sweet channel artwork btw.