I can think of several answers to this question, but I will try to limit my response to a few of things I have seen more often than others...
1. Do not neglect the "out of the way", take your pick:
Hay bale(s) in the middle of the 40 acre field.
Telephone pole surrounded by head high cane in the middle of the same field.
Grassy, willow choked slough about 1/2 mile from the nearest doe concentration. ( Have you ever noticed how many guys swear they saw the biggest buck ever while pheasant hunting?)
The middle of a taller CRP field.
Anywhere in a standing corn field of course.
Mr. Big can see for quite a ways in most of these situations and I think more big boys are bedded away from the heavy timber prior to the rut being in full swing and then again after the slugs start flying. They could be anywhere during the peak of rut of course.
2. Now in terms of classic "timber" type bedding areas...
I look for the confluence of two or more ridges in the timber proper. My thinking is this offers multiple escape options to a big deer. Generally, vision favors the deer here since they are high and they will play the wind too of course.
Similarly, a ridgetop that drops sharply on one side and slopes gently away on the opposite side, perhaps leading to a field, seems to be attractive. ( I have shot my last two bucks in this type of area BTW.) I know Old Buck practices TSI, and I would say leave a few strategically placed "tops". Deer love to nestle up next to those tangles, especially on ridgetops.
3. I liked what others said about the nearby house, etc. I have seen similar situations too. Similarly, even nearby heavily traveled roads can serve as a "backstop". It is almost as if the deer are conscious of a "known quantity" behind them. If something "sounds" different though, they become alert. In a way, they are eliminating a potential threatening approach.
Several years ago I had hunted a REALLY BIG buck on one farm and then shot a different one elsewhere, etc. Subsequently, I set out one day to take down stands, etc, and I decided to minimize my walking distance by driving down the development road on the backside of the property I was hunting. ( This road was fairly well traveled but people didn't habitually stop along the way and I had never approached my stand from this direction.)
I drove halfway down and pulled my truck over to side and jumped out, hopped the fence and promptly jumped Mr. Big. He was bedded 40 yards off the road and I believe he was "using" the road behind him as a barrier. With the road upwind and behind him and a great view of the valley below and heavy escape cover to either side, he was set. No wonder he was so big!