About add-ons optimization

[Malsomnus]

Hey, just thought I'd ask for some good tips for optimizing my add-ons. Any really obvious things I should do/ tools I should use?

So far what I've been doing is focusing on functions that run frequently (OnUpdate, UNIT_AURA, log events) and removing all calls to global functions/ variables, plus making sure no variables are created in that scope. The only tool I have for it is WowGlobalFinder, and, err, the game's default display of the 3 add-ons that take up the most memory.
What other techniques and add-ons should I know about? I can only assume there are a bunch of tips and tricks for working with strings and tables that I'm not aware of...