My first post about user interface elements was back in October? Seriously? Sheesh. Since then I've talked about unit frames, how your spells spread in space, macros, two proc tracking addons, keybinds, and shared some of my Weak Aura strings.
The final topic is to use a boss mod effectively as a DPS, even when you're not the raid leader calling everything. The two popular boss mods, Deadly Boss Mods (DBM) and Big Wigs (BW), both work pretty fantastically out of the box, but using a boss mod properly can really enhance your spellplay during an encounter.