Ok here I come, brace yourself!
1: Bars need to be the same texture/style, I see at least 4 different styles.
2: dump portraits, they're both a large memory hog (especially moving portraits) they're ugly (in my opinion at least) and they serve no purpose as you can see what they show right in front of your face ingame anyway.
3: I'd remove the name and level from the player frame, I'm assuming you know what level your character is and what name she has
4: The buffs hurt my eyes, I personally absolutely hate that style of showing buffs, it takes up so much more screen real estate that it should.
I personally prefer just having icons with a timer, because you know which buff/debuff it is from the icon anyway.
But if you like this, at least change it so that the icons are at the right side and the bars deplete that way so it doesn't constantly take up such a big block of space.
5: I would hide titanbar/fubar or whatever you have at the top, or at the least hide the texture and place the things you have at the left now in the center (and what you have right either center or left so the minimap can move up and free more screen space)
6: Remove/replace the border of your minimap, it doesn't fit the rest of your UI and the minimap is too large in my opinion.
7: And last but not least, I would download buttonfacade
to make the icons on your bars and buffs match your UI.
It's a purely aesthetic addon, but it's also very light weight. (0.1-0.2 mbish)
Other that that list, I'm assuming Zephoes is your focus target so I would add a target of target beneath your target.
And I'm assuming/hoping that your target castbar is as big as your castbar and above yours or something as I consider a large target castbar to be important in seeing when a boss casts something big and important.
(Or an enemy in PvP you wan't to CS etc)