Some days I'm partial to the Rowne Programming Elegance By Fiat method: "I touched that, therefore there is no more beautiful or efficient piece of code ever created. Behold! The laws of space and time warp to increase your fps despite my once-a-frame SetPoints! You may begin your praise now, I am ready to receive it."
Don't forget the many profiling tools Blizzard provides for us:
http://www.wowwiki.com/World_of_Warc...ging_Functions
http://www.wowwiki.com/World_of_Warc...ling_Functions
If you're unsure whether one way is more efficient than another, try doing it 100,000 times and seeing how long it took.