We have all had the experience of taking our mind off a problem only to have the solution come to us like manna from heaven.

Whether it is a creative answer to a difficult brief, an elegant way to write a line of text or even just the name of that actor from the movie you saw last night, it seems to come from within and it can be deeply satisfying when it happens. Archimedes, who devised a solution for measuring the volume of irregular objects while he was in the bath, will know the feeling.

The above is from an article called The Claws and Wings technique. You basically ask yourself a question and try to find the answer with any resources available to you. But you keep bringing yourself back to the question. You do this until you expand too much mental energy. You then let the problem go and let your Subconscious Mind take over. I thought of maybe just asking myself one question as a mantra for an hour or several hours and then letting it go. I'll see if anything pops up. This would seem much faster.

Here is the full article in detail:

http://lateralaction.com/articles/grow-your-imagination/