Learn to look for the outline of their ears... I found you'll see that before you see anything else; because most of the time, they are standing there looking at you. You just aren't seeing them!!
There were times my hunting partner and I both would be glassing a draw, and not see anything for SEVERAL minutes. Then one will twitch an ear and catch your attention, and you get to looking at that ear outline, and there's 20 sets of them standing there looking at you!
We spotted that ear outline first, when they were half mile away on top of a butte also. Had been glassing that hill for 5 minutes or better. Started seeing ears, and there were at least 7 of them up there, two of which were real nice bucks. Have also spotted it driving down the road 50 mph, on whitetails laying in brush beside the road. Once you recognize it, it's easy to see.
Expect them to be anywhere!
-- I've seen them sleep in the road ditch. Guy that was guiding, drove his pickup between two of them, got up the road 30 yards and jumped out and started pointing at both ditches. Not big bucks, but it was our first year, we were running out of time, and we took them both.
-- I've seen them bed in wide open prairie not 50 yards off the road. (But right behind the Posted sign!) And, that one was no little buck! 5 x 5 about 25 - 26 inch spread.
-- I've walked up to the edge of a wash, and found them 12 - 15 feet below me, without a clue I was there.
-- I've seen them way high on the side hills, just before they broke and ran over the top.
-- I learned in short order, before you squeeze the trigger, you look to see where the closest road is. He could break back toward the road, or there might be a road just over the hill.
-- Either way, it is a whole heckuva lot easier to drag that sucker down hill, than it is to drag/pack him up hill.
-- If you are 3 miles from the road, and it's all up hill tot he truck. Discretion is a virtuous quality!
-- If your partner doesn't posess it, shoot him when the buck jumps out, he won't weigh as much as a full grown muley, and will be much easier to drag out of there!!
-- Mule deer are only surpassed in stupidity by antelope!
-- Antelope are only surpassed in stupidity by one of my former hunting partners.
-- Always sight your gun in BEFORE - opening day, 1 hour to tee time, in the hills you want to hunt.
-- An inch and a half high and right at 40 yards is not good enough, when 4 monster bucks and 2 spikes go over the next hill, 350 yards away.
-- 50 yard wind sprints up a 40 degree incline, when you are severely hungover, should never wait until the 3rd round to start. Commence on the first shot, then you might have a chance to shoot before puking! If you wait until the third all you see is horns going over the hill!! (He said he was shooting behind them, I figured he was shooting somewhere over in the next county to the SW, the way he sighted his gun in.)
-- If you missed 5 times once with your gun sighted that way. Let the other guy shoot, next time you see them! (I wasn't with him the second time, or I'd have pretended it was 3 miles up the hill back to the truck!)
-- And, last but not least... It doesn't matter how big the one you hang on the wall is, you always remember the monsters you saw! No one can ever take them away from you!!
Good luck dude, may the God's of muley huntin smile down upon you!
