sometimes I make up songs during a long walk
There is no better design tool than a good long walk. It may not always lead to creative breakthroughs, but does reliably clear the noggin and put things in perspective. Before I begin to think about a particular project during a walk, I usually find myself simply getting into the cadence and breathing of walking, sometimes making up phrases and melodies to help me focus. Whether or not I make progress with the project at hand, I always return to the studio feeling relaxed and optimistic, eager to field the inevitable challenges of the day.