Wait 24 hours from time of shot or a little more until daylight, you can see better. I would go back Sunday morning around 7:00 with dog to site last site with good blood, good starting point to track. Mark along behind tracking dogs trail as he goes with toilet paper. Have 2 or 3 people about 25 to fifty yards off to the side of track. Look in creek, pond, or low spots near track. By putting the toilet paper within seeing distance of the last piece you can figure out areas near track to check, sometimes they will double back, hide in a gully, or low. If you still don't find him wait about 2 or 3 days and go to last good track points and make grid patterns around that position. Big bucks tend to run straight and hard sometimes if pushed, does like to make circles, or do with dogs running them more than likely. A buck will sometimes leave the area if pushed, but return in 24 hours or a couple of days if left alone. With dogs I have seen them run a certain trail out of area. People seem to get a lot of trail camera pictures, so put some out right off trail or feeding area now close to original shot. I went back a week later one time and the deer I had shot doubled back to spot I shot and died.