I found a good way to practice judging distance,and getting better at it.Is while scouting or walking to your stand,pick a point out ahead of you while your walking & judge the distance then when you get their see how close you were.Each time you do this you will be more accurate.
What do you do for juding distance?

I use a rangefinder.

Not a bad idea but judging distance is so much easier for me when on the ground. Once you get up 18' the perspective changes everything. I use my range finder and guess dist. than check with range finder.