All kidding aside, I consider a good rangefinder part of my essential equipment...like American Express-- I don't leave home without it. As a bowhunter I don't like to feel like I have to depend on some electrical device...but whatever works for the best humane kills. I make it a regular habit while in the stand to range different objects after I guestimate the yardage. It improves my yardage judging skills and helps to pass the time on stand. BTW be sure to have extra batteries on hand. Another thing I like to do is I have a 3D target with a stand which I have a buddy move around in the yard at different yardages to get a feel for the distance. Try these, I guarantee it will help.

It happens to the best of us. Always remember that target shooting is totally different from a live hunting shot. Sometimes the adrenaline gets so strong that I almost come outta my tree. When you are hunting a big deer "what can go wrong will go wrong"!! Just keep practicing and next time you'll be better prepared for that close encounter!!