Sound advice here for blood trailing. The first things I do after a shot is listen for a while then take out my compass. Usually after the shot I can here the deer crash through the woods then one load crash or a dull thud. To me, this is the likely spot the deer went down. I take a compass reading of where I shot the deer, where I last saw the deer and where I last heard the deer. As most of you stated, everything looks different on the ground or after you have been turned around for a while, but a compass reading will always be the same. If I do not find blood at the first spot, I know by the compass reading the direction I have to go, as it is the line the deer traveled. I try never to skip ahead and always stay on the blood trail. I have recovered deer withpoor to noblood trails by walking the compass bearing to the last sound. I just stay on the bearing looking for the deer or any sign. This is especially helpful on rifle hunting when the shots can be greater distances.
On very difficult tracks I will occasionally hang tissue paper in the trees at blood spots. This gives me a place to go back to if I get off on a different trail, allows me to look back and see the general path the deer was running and is quickly biodegradable if I forget to pick them up.