It's a simple thing to say, but it's easy to get caught up in doing things you love, and not take enough time to get some shuteye. I'm certainly guilty of not getting enough sleep, I have a toddler, after all. But once in a while I'm good to myself and it really pays off.
For me, the more sleep I get, the more I dream—and I'm blessed with pretty cool dreams. Once I get to eight hours, ordinary becomes extraordinary and I'll occasionally move into the lucid dream state. That's always a trip. But along with all the coolness come some really great images or ideas—impossible things never before thought of. Dreams are good like that—they don't care about reality.
So if you find yourself in a creative slump, try loading yourself up with sleep—a lot of it. Sure, eight's nice, but see what happens when you head in toward ten.
Also, write those dreams down quick—they'll slip through your fingers before your first cup of OJ. Write them down even if they have nothing to do with your art or anything your interested in. Dreams are kind of vain—they like knowing that you care enough to remember them. Jotting them down is the best way to get your head to start paying attention.
So, if you're showing up blank at a blank page, go get some sleep. Make time for it. It's important. Let me know what you see.