Post your UIFollow

To be honest, I don't think there are any 'guides' to making your own UI. You generally just download a bunch of mods and customize them in a way of your liking.

Aside from that, I can recommend you start out with either Pitbull Unit Frames or X-Perl UnitFrames and Bartender4. These addons allow you to modify your unit frames and hotkey bars pretty much any way you like them, and those two aspects of an UI take up most of the screen. At that point, you can use a mod like IceHUD if you want a heads-up display, a mod like Cowtip or TipTac to modify your tooltip, and/or a mod like Recount which functions as a damage meter.