I have always had luck tracking the route he most likely took. Generally a hit deer will follow a direction and most of the time along an established run especially if the area is thick. I normally am looking for jump marks in the dirt or leaves if no blood is there. If there aren't fresh hoof marks I check the next run and so on. A running deer always leaves fresh marks. At some point when the life lights are going out the hard hit deer will often jump off and curl up in a thicket or blow down and die. What really sucks is 3 days later when the birds are gathering and you find it all picked apart especially if you were close to finding it. Hard to see the brown especially if they are curled up but look through the thickets for anything white even if very small. Normally unless you are in with birches nothing white will be in thickets at least here in Vermont