Great advice. One personal difference for me. I fish midges in faster and shallower water (<4 feet) generally speaking. I find the fish respond better to it in these depths. Deeper water to 15 feet or so shows better results with pheasant tail nymphs, scuds, sowbugs, or other patterns.
I think the midges are in the faster water and there is larger aquatic life in the slower water. The big bugs work in deeper water and I vary their size depending upon clarity, speed, and fish response, make them obvious for cruising fish. I will fish the largest pattern they will eat as it holds the fish better and may also allow for a larger class tippet. I have fished scuds up to #8 hooks and broken off fish on 10lb tippet...
Use a very long leader >15 feet at least, I can stand the fish seeing me more than they will stand the fly line going over their heads.
I fish the largest indicator I can get away with but I fish a very small one in water less than 4 feet and I try to use browns, greens, and blues, in the shallow water. Over 6 feet I use bright orange or reds to help me with long drifts over the length of my entire fly line plus some backing. I only fish one fly at a time. You lose less flys that way and end up catching more fish. Learn to fish one fly well, don't hope two poorly fished might improve your chances.
#1 drag free drift. If you can't do it, you are wasting your time until you learn how to make it happen. You can stand in good water and catch fish at your feet. They don't care. Let the line drift down below you until you learn how to make perfect drag free drifts the length of your fly line. Then learn to cast and make them drag free.
I caught over thirty trout one day within five feet of a buddy's feet. He was standing in waist deep current. Those fish saw him. I watched them eat the fly. Now big fish require much more stealth, but those are fish over 20".
Food for thought.