How to Solve It, by G Polya

(via Brodie's Thinking Forth: A Language and Philosophy for Solving Problems)

• Determine your goal.
• Picture the problem as a whole.
• Develop a plan.
• Think of an analogous problem.
• Work forward.
• Work backward.
• Believe.
• Recognize the auxiliary problem(s).
• Step back from the problem.
• Use whole-brain thinking.
• Evaluate your solution. Look for other solutions.