There are many good points here.
My suggestion is probably going to allow you to sleep at night (1st hand - the hard way)...
Clear your shooting lanes as far out as you comfortably shoot and stick to them.

Here's my example, once I've selected a tree to put my stand in (taking wind and deer travel into consideration), I set my stand approximately 14-18 feet high.
I believe that you can still make a good downward shot @ around 8 yards, if needed, and not effect the angle going through the deer/organs too much.
Get in your stand and pick the trails you want to shoot towards, and prune all necessary branches on the trees / bushes, etc. out to 30+ yards
(which is my maximum "comfortable" shooting distance) about 12-24" wide.
Note: When you select the trails you want to shoot towards, try and select shooting lanes that will allow the least amount of cutting as possible.
Typically I'm in trail junctions or around food sources, so I might have 3-5 shooting lanes.
Also if you have a choice, try to pick trees that lean back 5-15 degrees, like a chair for comfort, if possible.
I like thick cover and in NH we have lot's of trees and I try to pick a Spruce if possible as it gives better cover along with natural scent protection.
Then either mark those distances with tape (I prefer not too), mentally or by natural features, like a rock or something.
Now you need to stick to those shooting lanes, because when the "magical" time comes together it will either be in a low light situation or adrenaline will kick in and you won't see those TINY branches that deflect an arrow easily!
Just remember ~ Arrows are not bullets!

In case you haven't read this it's worth reading!
http://www.huntingnet.com/forum/tm.aspx?m=2987754