It's difficult to try and explain it in detail here on a forum. There are hunting and shooting books that detail it. Also a good instructor or hunter could show you.
If it's already been bore sighted, then set up on a good benchrest at 50 yards and fire 5 shots aimed at the bulls eye on the target. Don't look at your holes until all five shots have been fired with the cross hairs on the bulls eye. Now look at your groups of bullet holes. Where did they hit on paper? Probably not on the bulls eye. Count how many inches horizontally and vertically the center of the group is from the bulls eye. 2 MOA moves the center of impact about 1 inch at 50 yards and 1MOA is about 1 inch at 100yrds, 1 MOA is about 2 inchs at 200 yrds. Move the dials in the direction you want your bullets to move, it's important to keep your cross hairs aimed at a consistant spot (bulls eye) while sighting in. Don't chase your bullet holes. Once you sighted in at 50 yrds, next move to 100 yrds and fine tune it the same way.
Everyone has different ideas about trophy pictures. Looks around and you will see "long armers," "set behinders," "big cheesers," and "blood covered brutes." I have a few tips to keep your trophy pictures from being laughers or worse yet just plain gross.
#1 Clean it up. Try to avoid bullet holes, gut pile, mass amounts of blood, and the tongue sticking out. You don't want your big buck to look like a angry 1st grader with his tongue out or a MMA fighter during the 3 round.
#2 Long arming...