I’m currently rewatching Mad Men. In a recent episode, Don Draper explained his method for producing ideas: “Just think about it, deeply. Then forget it. An idea will jump up in your face.”
Draper encapsulates the advice put forward by James Webb Young in his classic book, A Technique For Producing Ideas: fill your head with as much as you can about the problem, then think about something else.
That really is all there is to it, but of course there’s also much more to it than that.