1. Take care of my physical health. Body first, brain second.
2. Address distractions. If I'm stressed about something I can deal with it and go away, my mental function rockets up. Likewise, if other areas of my life are competing for my time, and I get organized and address them, I have a lot more mental energy for writing.
3. Feed my brain. My brain is happy with a lot of input. Watching great films and reading great scripts is the obvious start, but I find any kind of quality writing (especially edited writing, which is becoming harder to find) makes my brain very happy, whether it's fiction or non-fiction, general or specialist, technical or non-technical. And interacting with the world is good input, too. One trip to the farmer's market, for example, and my brain is buzzing for days.
4. Write notes for friends. It tricks my brain into shifting into "screenwriting gear" without any perilous ego investment. Plus I know some brilliant writers so reading what they're doing is always exciting and motivating.
5. If I'm stuck on a specific project, most of the time the problem lies in Prep. If I go back and check I've skipped something in the prep stage that's causing me trouble in Pages. So I go back to Prep, make sure I've covered my bases, fill in any gaps, and voila: unlocked writer.
6. Hang out with brilliant people. I don't get to do this in "real life" very much, but I find hanging out with brilliant writers, even in online spaces, is really motivating and energizing for me. That's why I love the comments here at GITS and why I'm so grateful to the participants at the
GOYOQ Forums (where you are very welcome, btw). Hearing about other people's travails makes me feel less alone, hearing about their successes makes me feel like writing is possible, and helping to troubleshoot their immediate writing problems and challenges makes me feel like I have something to contribute and tricks my brain into screenwriting gear, too.