How to Solve It

George Polya's How to Solve It suggests the following steps when solving a mathematical problem.

1. First, you have to understand the problem.
2. After understanding, then make a plan.
3. Carry out the plan.
4. Look back on your work. How could it be better?

His book contains a dictionary-style set of strategies, but is not a cook-book. See also heuristic.