“If you have more than one pressing idea problem, create a Problem Queue. (You can never have too many good problems to work on.) As you unwind for sleep, select a problem from your Problem Queue and let your mind play with it in a relaxed and unfocused way. You might even spend a few minutes doing some related reading. Don’t force solutions, though. What you’re doing here is luring the interest of your subconscious. Ponder the relevant details, but don’t try to make everything fit together yet.”