Your ui is Blank, Boring And stale.
1: Your font is very hard to read, your chat log is a mess.
Cure: Add chat windows, one for guild/officer/Raid/Bg/Party/Wisper/RealID,Then remove them from the General frame.
Add another window to show loot and remove all the loot options from General.
This way you can read things you need to see like how to kill a boss or what your guild/friends are saying.
And you can see trade chat etc, your not bogged down by every loot roll trade general spam and your raid trying to tell you to get out of the fire.
2: Your ui is simple yet stale, you should add rbottombarstyler to the ui so your spell bars dont look so bare.
You can change the look between aion and diablo styles by default or add your own art.
3: Damage meeters are nice but you should not tailor your ui to have a spot for them, as they should be turned off in combat to not distract you causing dps loss.
4: Can't See in your picture how your showing your self target and all that unit frame jazz.
You should give the blizzard style a better run, or xperl.
5: Whats the point of such a high resolution and large screen space when its all blank like that?
All you basically did was take any of the art the game had out and gave nothing back to fill the blanks.
Here is my warlock.
Rbottombarstyler, to make the bottom feel more like a game ui.
Sexymap like you however each toon i use gets one that fits the class.
Xperl unitframes, only downside is /focus vs right click, errors.
Necrosis for warlocks, but this pic is old and i no longer use this one.