This is more of a WeakAuras UX than UI question I believe.
Let's use Frost Mage as example. It has a couple of procs it needs tracking: Invoker's Energy, Fingers of Frost, Brain Freeze, Frozen Thoughts...
1st question: What is most visually noticeable display for managing (bars, icons, textures, texts...)?
a) keeping buff/debuff uptimes
b) noticing power gain procs
2nd question: Assuming best display from question 1, where should those displays be positioned on the screen (relative to your character) so you can track them without having to fiddle your eyes too much on the screen?
3rd question: What are the best colors to use? Should you use single color theme for all or use specific colors for different buffs/debuffs?