I started dabbling in the UI thing way back when Gypsy was new and haven't stopped since then. I did something new for me on my last UI incarnation--I used a compilation. While I enjoyed it greatly, I still felt a little funny not building it from scratch on my own. So, I trashed my entire Interface and WTF folders to start from scratch while pulling bits and pieces from different UIs that appealed to me.
While designing this one, I had a few priorities in mind and I hope they're reflected in the final product.
This UI needed to be flexible. I need to use the same thing for raiding, leveling alts, and doing battlegrounds and arena. Additionally, since I tend to go resto in PvP and feral in PvE, it has to be able to cover both of those roles (I previously had a vertical raidframe on the side of my screen that was a nice low-impact raid frame for feral, but was a pain in the ass to use to heal people). It's also not just for me--my fiancee is getting her own computer/WoW account and I wanted to make something both of us could use. That's one reason why the action bars are shown; I may know where all of my main's skills are, but I don't know for some of my newer alts nor is hiding the action buttons a very newbie friendly idea.
Some of my alts have pets, so I had to find a place for the pet frame. Plus it comes in handy for weird ass quests Blizzard likes to throw your way. I wanted to show party pets, also. Partly because I had room for them and partly because I really hate having to hunt for them in the game world whenever the owner wants to get them buffed/healed/whatever.
I wanted prominent unit frames. The last UI I used had some low placed unit frames that I couldn't see out of the corner of my eye while playing, so I simply bumped them up higher. My combo point display (IceHUD, and the only thing I use from the HUD at all) is likewise placed very prominently.
I was also hoping to have a UI that looked like it fit together. I stuck with a grey/white color scheme and used the same font/texture when possible. It really does a lot to tie everything together.
There are a few things I didn't manage to remember to screencap. Omen fits on top of the minimap when I'm grouped. I have PowerAuras and I'm enjoying tweaking that--right now I just have a reminder on my shaman to cast lightning/water shield, but I plan on adding a few other settings to it. PowerAuras is a nice low impact way to monitor various things.
I would like to find a way to raise the contrast between the health bar and the background, though. I wanted to make the background a darker grey/black, but I haven't found a way to do that quite yet.
Thanks to the various contributors on this forum who post their ideas for me to shamelessly pilfer.
Solo shot of shaman alt w/ loot frame and faded party windows
Solo shot of druid w/ combo points, classtimers, and MSBT
Party layout
Raid layout
Addon folder