Basically deer bed where they feel safe and as Gene and Barry Wensel discuss in their writings, big bucks have to be thought of as another species unto themselves. So finding deer beds and big buck beds can be two different things. We just bought a 23 acre hunk of forested wetland. No mast on it, but it has marshes, blueberries and appears to be a bedding/travel corridor. We know that at least two bucks share the area and are pretty sure about the general area they bed. We have plenty of pictures of them and they always come from the same direction. The does and yearling bucks have plenty of mast this year and in such years they are hard to pattern. They eat, bed down near where they eat and when it's time to eat again they get up and eat. What works best for us is to find where they are feeding. Eventually, if your set up is accessible without disturbing the deer they will show up. You can also backtrack from the feeding areas and at least get a general sense of where they are coming from. An early snow can make this quite easy to do.
One way to determine where the deer feel safest is to follow a long blood trail. I am not advocating poor shot placement but I have been amazed on more than one occaision when trailing my own or other's deer where they take you and what you can learn. One deer two years ago took me into a blueberry thicket that I was totally unaware of even existing. If you have friends that hunt nearby and they need help trailing get right into it with them. It's nice when deer go down quickly from a shot but when they don't and you can trail them in daylight and you pay attention as you go you will be surprised at what the deer will lead you to.