One of the best pieces of advice I got...tell yourself a story in your head. Pick a book, movie, show, game, whatever you're very familiar with and tell yourself that story. Start from the very beginning and be as detailed as possible. You'll be out in 5 minutes. I used to do it with KotOR but after a while I got so familiar with it that it stopped working.

Nowadays I write like Star Trek fanfic with convoluted explanations, and attempt scripting out new movies in my head