One of the most important things you need to know when bowhunting is precise yardage. The first thing I have my hunting partner do after I'm all set up in the ground blind is use a laser rangefinder to give me some exact ranges to known objects.
I like to know what landmark is 20 yards, what tree is 30 yards, 40 or 50 yards. That way when my target walks through I can easily judge the yardage accurately.
We owe it to the animal to make a quick efficient shot. Many misses occur by misjudging yardage. Spend the extra time to get familiar with your equipment, use it in practice and while zeroing in your bow.