2. Too tired to conspire. Native Americans supposedly sometimes stayed up well past their bedtimes to let their minds roam and have answers to their questions. When we stay awake well into the night, and become too tired to really think, our brains can go on outrageous rambles. While this is not for everyone...perhaps a bit of it might work for your plotting.
3. Fifteen minutes on a treadmill. Don't overdo it. Movement helps creativity. See if it works for you. But again, take it easy. You can do too much of a good thing. I suppose if you added 2. and 3. together, you could get to bed earlier.
4. The Green Eggs Theory. Write at the park, in a car, at the library, in the yard. Anywhere there is an outlet or your batteries work...just leave your usual space and find somewhere new. If it's at the library, you will be telling your brain to get busy. You didn't leave the house just to waste a few hours staring at a keyboard.
5. Directionally Challenged Creativity. Go the opposite direction in your story. If you were planning for a hero to kill the bad guy...have him save the bad guy's life. At least first. Then...whatever...
6. (An extra one in case you really don't like one of the above.) What the Dickens? A mirror. Put a mirror in your workspace as Charles Dickens did. Then you can move your hand, wave and arm, and you'll have those motions played out in front of you to describe.