2 things, being in the woods and scouting constantly during the season and being willing to get out of a tree and hunt from the ground if it fits the spot better.

I scout constantly during the season. There are so many things that are changing during the season that one must stay on top of. A hot acorn or apple tree, newly developed rub or scrape lines, fields that are suddenly "hot," amongst other things. My last two bucks, both 3.5+ andP&Y, were taken because I was on the move and scouting during the season. THe first I found a hot trail running into a cornfield where there wasnt one before and it had new rubs on it that werent there before. I set up a ground blind in some thick sumac one afternoon and tagged my buck 45 minutes later. THe second, I found a subtle funnel that had developed a heavy rub line in it. In the afternoon I built a ground blind, came back the next morning and killed my buck.

I also know way too many people who find a good spot to hunt, but dont, because there isnt a tree suitable for a treestand. Who cares! Grab a handsaw and build yourself a small ground blind. You dont need a treestand or even a pop up to kill deer.