I've been working on my UI for forever to get what I want, and I "think" I am finally there.
When I first started looking at healing beyond 5 mans (I just used party frames for 5 mans) I installed Grid. At that time, Grid was my only addon. I had a completely stock UI with Grid shoved into whatever nook it would fit into.
Over time, I added some new toys, like Dominos to get more control of my (far too many) button bars. I installed Omen and Recount, because, well, I was told to. Pally Power was the same deal, my guild said I needed it, so I installed it. All those things just got kind of crammed onto the screen and made a usable UI, it just wasn't pretty.
[img width=400]http://www.perasite.com/images/perasite1.png[/img]
I REALLY wanted to try kgpanels, but my first attempt at using it was a massive failure. I just couldn't figure out how to set it up, so I gave up. After finally finding a tutorial on configuring kgpanels, I decided I was going to make myself figure it out. Grid is front and center, always. Over time I've learned to be more situationally aware and not focus solely on those raid frames, but keeping Grid just below my toon's feet allows me to see what I'm standing in and respond quickly if it happens to be fire. It also means I've got my eyes in the center of the screen so if I need to see anything else, my eyes don't have to move too far.
This screenshot is the final product, when I'm not grouped. I could have it hide Pally Power and my single lonely Grid frame, but I'm so used to using them that when I go to buff myself or heal myself while doing dailies, I'm lost without them.
[img width=400]http://www.perasite.com/images/perasite2.png[/img]
The final screenshot is in a 25 man raid.
[img width=400]http://www.perasite.com/images/perasite3.png[/img]
There are a few items that aren't shown in that shot, so I'll list off all of the addons I use and their purpose:
kgpanels - borders around buttons, map, chat, etc
Grid - raid frames
SexyMap - makes the minimap just a bit less ugly
ButtonFacade - makes your buttons a little prettier
clcbpt - I have this show up just to the left of my Grid frames and have it's warnings pop up just above Grid (basically on my toon's feet) This addon is specifically to track Holy Pally timers (Beacon of Light, Sacred Shield, Judgements of the Pure, and the SS HoT)
DBM - boss mod
Chatter - chat box mod
Skada - replaced omen and recount with Skada and now my Threat meter shows up during the fight and damage/healing meter shows up when the fight is over
Pally Power - helps manage buffs for multiple pallies in a raid
Satrina Buff Frames - gets my buffs/debuffs under control allowing me to place them exactly where I want
TipTac - allowed me to move the mouseover info pane to where I want it and make it look good
Xperl - Unit frame addon that let me position my personal frame, target, targets target, focus, and focus target to be exactly where I want them while making them look nice at the same time. In the screenshot, you can see that I'm targetting myself and that my target's target is shown just to the right of my target. The focus and it's target are positioned just to the right of that.
Wow, that ended up being a longer list than I expected. But having each of these gives me all the information I need during a raid while allowing me to be pleased with the overall feel of my UI whenever I sit back and just enjoy the sights of the game.