Creation of theme is a complex process that demanding considerable efforts. Besides that you draw a theme so you still should understand with complex files of a theme.
But now creation themes for sShutdown became easy, now it is possible to concentrate on inventing of a theme, instead of on that how to describe themes in files.

Simply draw a theme, and then visually positioning buttons and choose effect for a background and the theme is ready.

But what for words if it is possible to look at the convenient interface of the program:

Options of effect for a background