Ok so most of you will find that I'm an addon junkie. I only turn them off before patch day so I don't end up limited by broken addons.
All of my screen is built upon the simple fact that all of my abilities are hotkeyed except a few hidden buttons at the bottom of my screen for res.
I use a combination of ctrl/alt/shift hotkeys in conjunction with mouse thumb and middle button to streamline the class i play and it's abilities. I also use click casting with hotkeys designed to allow easy decursing and healing.
All of my pertinent information is listed on the left and right side of my screen, with left being cooldowns on abilities, and right being cooldowns on trinkets and such.
I have specialized macros for nullifying interface error messages and sounds, beginning auto attack, while activating trinkets and abilities that increase dps, then activating my special ability linked to the macro (i.e. mangle or crusader's strike) and if there's a demand I'll post it when requested.
Buffing is handled by rotating my mouse wheel, and it's set up to seamlessly negotiate party and raid buffs, as well as single buffs out of party.
Any other questions just whisper me in game or post a reply

My interface folder is listed with these mods:
Arkinventory
Auctioneer
Buttonfacade
Buttonfacade_trinity (can't go without that one!)
Cartographer
Cartographer Questinfo
Chatter
Clique
CooldownTimers2 (don't get 3 it sucks)
CT Mailmod (the old standby from the past!)
Elkbuffbars
Enchantrix
Enhtooltip
Gatherer
Gatherer Hud
Gatherer Wowhead database
Healbot
Informant
Lightheaded
Macaroon
Mounted
sct
sct damage
sexymap
Stubby
Xperl
ZOMGbuffs
Oh how I love my addons!
Theres an attachement with the picture of my UI, but you have to see it to appreciate it!