Judging distance.

Whether you just use a gun or a bow or both you need to know how to judge distance if you do not put yardage markers out to make it easier on yourself.  The best way I have found to judge distance is when you are practicing shooting, practicing at a specific range will allow you to visualize how far away are and you can use this in the field.  Say you have yardage markers set up at home for practice shooting your bow  after you are comfortable with these yardages take the markers out next time out and judge yardage for yourself.  You should have the yardages you practiced at memorized by now and if you look too close to the target then you probably are.  This will help judge closer yardages such as twenty through fifty yards, anything more than fifty I would suggest having yardage markers out at the furthest point you feel comfortable shooting at and if a deer walks within that range take your shot.  Now if you are really good and do not need yardage markers then kudos to you, I have been hunting eight years now and have still not mastered memorizing the longer yardages yet.  So get out and practice and get to memorizing your yardages and you will become a better hunter.