If I am really stuck in a rut its always good to do as randle says, step away from the computer for a little bit and look at the world around you for inspiration. Anything from advertising, to newspapers, to packaging whenever I go shopping. Anything designed by designers can add a different perspective to your project.
Also, I have a folder in my bookmarks labeled inspiration, its mostly websites of designers i like... or photography websites such as
[daily dose of imagery]
This sort of thing just gets your head thinking creatively but not specifically about one design you have to do. Read a quick tutorial and try a new technique, it will eventually incorporate itself into your designs.