I would actually AVOID making a formula sheet or index cards, unless you can use them in class on tests. It could just be me, but they seem to be TOO easy to access and thus discourage me from actually learning the formula. This could just be me though. I think its best to work problems while looking at the formula in the context its presented in the book. That way you aren't just memorizing a bunch of letters, but the origin and theory behind that formula.
Another thing, break down formulas in your head by thinking about the factors behind them and whether increasing the numerator/denominator results in an increase/decrease in the overall equation.
For example. F=G(m1)(m2)/(r^2).
If you imagine bigger bodies (sun and earth) versus two people (hopefully), you will remember that there is much greater gravitational attraction, and that masses belond in the numerator. But then if you think about what happens when you spread them out, your gravitation force decreases.
Its an easy example, but the thought process can be applied to any equation. I found this especially helpful in EM physics.