Maurice Vaughan at 2010-07-10 16:11:18:
When I feel my creative engine is running low on fuel, I think of new screenplay ideas to get excited about writing again. Nothing, I repeat, nothing gets your engine roaring like new ideas you picture inside your mind that'll one day be made into motion pictures. Once I do that, I can jump back into my current project with a full tank.
The Writer at 2010-07-10 21:53:20:
Most days, after doing the grad student job for 6-10 hours, I'm feeling pretty brain dead by the time I get to delve into screenwriting. Oftentimes, I don't feel creative or funny or in the mood to write. Here's what works for me:

1. Do something else that is creative: gardening, drawing, coloring, painting, and so on.

2. Do something else that is relaxing: have a massage, read a book on a completely different topic from school or my scripts, play a game, go for a walk, etc.

3. Take a nap. Dreams can be inspiring.

4. Meditate.

5. Visualization or simply daydreaming.

6. Go out of town, preferably to a big city with lots of creative energy.

7. Watch movies or read scripts.

8. Start a brainstorming notebook where you just sit for 30-60 minutes and scribble out ideas for stories -- a few sentences each. I force myself to keep coming up with ideas no matter how good or bad, to keep my mind thinking creatively.

9. Have a long conversation with your funniest friend.

10. Red wine.

This is what I do. I hope this helps.

TheWriteScript
http://thewritescript.blogspot.com/
The Unknown Lyricist at 2010-07-11 08:43:42:
1) Go stream of consciousness... knock out three pages of whatever comes into your mind. There's no pressure. It doesn't have to be good. It just has to fill the page. As you do this, a lot of times, sparks fly.

2) Use reverse psychology. Some mornings when I don't feel like writing... I dare myself... "I bet you can't even write a page." Sometimes, by articulating your fears, you can neutralize them.

3) Write Shit. Literally. This is sort of a variation of #1. Just fill the page with the word "shit" or another cathartic word or random nonsense. Sometimes I just hit random keys for paragraphs. It just feels good as the jumble of letters fills the page. A lot of times, it just purges all those negative emotions.

Of course, your mileage may vary.

Greg