Good post Top Shot. You covered it pretty darn well. I will add a little of my own methods and indicators I look for other than the ones you listed and a little on how I see it.
Verticle wind or as I call it "Lift" Pine trees are a great indicator. If they are moving and appear to be flapping their limbs like they are trying to fly but no left or right lean is obvious, that is lift. Most of the time shooting 1000 yards and on out to 2000 it will be from 1/2 moa to to 1 1/2 moa of lift. I usually go for a 1/2 to 3/4 moa on the turret and time the shot where the flapping is least.
Morning light fog is the sweetest indicator. Like painting the wind. I have sit and watched it move for hours to learn what the terrain below does to it.
Give me dead still light fog and I will have the confidence I want for that long shot on game.
Here are a few pics of fog and wind currents.
If I am shooting aross a canyon I will be watching the very tip tops of trees between the gun and the target. That sprout going out the top of an everygreen tree is a great indicator for direction and speed. Plus they might be up where the bullet will arc depending on terrain.
On game I will look for these small but important indicators. Breath steam from their nose for wind direction and speed. On antelope if you watch long enough, and if it is dry enough, one will move and leave a little dust off their feet. Small to look for, but a good indicator of direction of wind at the target.
Also in some cases I have seen the long hair on the mane of an elk move too. If I see this there is a brisk wind at the target and I real in all the distance I can or pass.
Wind at the rifle trumps all other. It starts the bullet off path first and that direction or path will be hard to over come by wind at the arc or at the target. It is a common mistake to let down range wind, even if a complete different direction, over rule all of the wind at the gun. So give the wind at the gun the most value. It is also common to want to underestimate the wind at the gun. As TopGun said, if you are shooting across a canyon you can bet it will be stronger in the middle. So don't be affraid to add a few MPH to the wind at the gun. I sometimes will double it depending on clues from other indicators.
Mirage.... Not as easy to read as some like to talk. I go slightly off focus on the target and read it there. I also on some occations will pick a point 1/2 way to the target and go slightly off focus to get a reading of mid wind direction. But be careful here. I want to read the mirage in mid air. It will always look much faser off an object like a deadfall or a hot rock. So look above objects for a truer reading.
My advice to beginners would be this. Use a quality wind meter like kestrel. Read the wind at the gun and go with the higher side of the reading to enter into your program. It will get you close and if it is a consistant wind will put you on.
Wind Rules on long range shots. I do not in any way claim to have it mastered. But I practice alot and I have gotten much better. But, if the conditions are not good for the distance I real it in to where I am confident or I pass on game shots.
I also do like Top Gun suggested. If I miss a rock I watch the splash if visable and try to learn what just happened. Plus I spend quite a bit of time in the spring shooting from my favorite vantage points for hunting. And I keep a good log.