The real trick isn't optimizing your code but optimizing your solution. Maybe you can write the same code three different ways but if that code implements an O(N²) algorithm when there is an O(N) algorithm that will do it doesn't matter much whether you shave a few microseconds off each iteration.

Successfully choosing the right algorithm takes careful consideration of the problem. If there is a secret to it at all it's probably choosing the right representation for your data. How to do that is a matter of experience and education. There isn't a cookbook solution to it because it usually depends greatly upon details of the problem you need to solve.

-sauoq
"My two cents aren't worth a dime.";