Decoyer- You asked a big question, but I'll try and answer it as best as possible. My choice of stand placement really depends on what I am looking to shoot, be it a doe for the freezer, a young buck, or whether I am really holding out for the big one.
First, I look for the basics: a food source, bedding areas, well-used paths, etc. I really try to spend some time beforehand looking at maps or even aerial photos (like those used to make soil maps) for natural funnel areas. These might be where two treelines converge, where several ravines come together, narrow areas of cover between two sloughs, etc. These funnels naturally concentrate deer.
Second, you will notice, with some scouting, that there will normally be well-travelled paths a few yards into the brush that parallel open areas. These parallel paths are used by deer to travel just within cover so that they don't have to travel in plain view. Although these paths will be tempting, avoid them.
Now, follow some of these parallel paths awhile, and you will notice less-travelled paths that cross them perpindicularly. These perpindicular paths are used by deer to cross the cover. If I am looking to shoot a doe or small buck, I will try to set up on one of these perpindicular paths that is used by deer to move between bedding and feeding areas. These types of setups are best for afternoon hunts because the deer will walk right past you to feed. For morning setups, try to set up on one of these perpindicular paths at a point where you can intercept the deer as they move from feeding areas to bedding areas.
For the real big boys, you have to get further back into the cover. Setting up for a monster is more area-specific. However, if you continue on one of these perpindicular paths further back into the cover, you will eventually find some secondary paths. What you really want to find during rut is some paths used by bigger bucks to check scrapes. Therefore, look for secondary paths that cut across the cover that will allow the bucks to check scrapes quickly. I have had most success setting up on paths between scrapes than I have setting up over a scrape itself.
Always set up with the wind in mind. Also, avoid setting up right on top of a trail. I always try to get at least 15 yards off a trail on the downwind side. A 15 or 20 yard shot is a gimme shot if you have practiced. Plus, you can get away with a lot more movement the further you are off the trail.
Last, all the gadgets in the world will not replace good scouting and lots of practice. Therefore, spend more time shooting and scouting, and less time reading the Cabelas catalog.