I just wait it out. I'm guessing you mean thinking up concepts for a game, along with the storyline and such. If so then I do what I previously mentioned: I wait. I just wait until some inspiration hits me and I get an urge to create something again. For example, I am now working on a fairly cliched game just to get out some ideas and to have fun.
Just think of a basic concept and build something upon that, making it as complex as you feel it should be or vice-versa.