Some background: something that I learned while going through school was human/machine interfaces as it relates to flying aircraft. As a flight instructor, when I teach students how to fly in the clouds by only referencing their instruments we teach them to have a scan. A scan can be any sort of pattern that you need to hit all the information you need and crosscheck it with other instruments. The two primary methods we use are a "T" or hub-and-spoke, or a box pattern.
I designed this UI to work on a hub and spoke technique that I use while flying. I look at the center of my screen which has my most important information like where I'm standing, CPs, and Procs. I then shift my eyes right to look at my DoT timers before going back to the center and proceeding down to my resources and health. Back to center and then left for boss health or casts. Rinse and repeat until I hit everything, timers, raid status, mechanics.
Other tips I can provide with this, orient your UI where you're most important information is located near each other, Use audible cues for very important things, everything that is non essential should be disabled (TURN OFF YOUR DAMN METERS). Once you have it set up the other important parts are to not fall into the three traps with a bad scan, Fixation, Omission, and Emphasis. Fixation is straight up tunnel vision which we all know is bad. Omission, you're missing something critical. You may be seeing all your UI but what about mechanics or boss timers? Emphasis is a bit of in-between. You can solve any of these issues by making sure you keeping up your scan or adjusting you're UI to maybe better suit your scan. The biggest thing that I have to teach my students is that scanning can degrade if you don't do it often. Get into LFR or dungeons to practice your scan because we only raid 2 days a week. Fix your bad habits and bring them to raid where you will see a difference.
If you have any questions let me know and I may be able to share some of my background experience with this because these are the UIs I have to deal with.