1. Go for a walk. Simple. I'm sure you've heard it before. But honestly, it's amazing. It doesn't have to be long. Just go out, stretch your legs, and feel the sun on your cheeks. Bliss.
2. Read a book. Reading isn't the same as writing. The story is already written. All you have to do is enjoy it. Go for the ride. Sometime I even find errors in published work and that helps me remember that all writers are human. All of us make the same classic mistakes. That way when I go back to my writing I go in with refreshed confidence.
3. Go see real people. Once again, I know sometimes people are busy and can't go out at the drop of a hat, but when you can, go out and be with people in the flesh. It's nice to have a laugh with best friends about meaningless things. My friends and I will laugh until we cry about one thing and when we look back on it later we wonder what we found so funny. That's the beauty of it. It doesn't matter. All you needed was a laugh and that's what you got. When you're back at your writing desk you're ready to start again.
4. Find other writers and talk about each others works. This way you're still getting in practice but your mind is on someone else's work. Plus, it's amazing to have an outsider's opinion.
These are the top four things that help me. I wish all of the aspiring writers all the luck in the world.