Ever find yourself looking at a question on a test or homework assignment and thinking, "man, we just went over this today but I just can't remember!" Well, a helpful place to start in that situation is to go over the most basic knowledge you have of the problem. What are the basic properties of the numbers or equations you're working with, what are the basic elements related to what you're being asked, what are all the formulas you know that might apply? Start from the basics and work your way up to the problem at hand, and maybe something along the way will jog your memory on what you need to do.