All of the good blood dogs I've seen got that way by tracking a lot. The dog needs to be put on as many trails as possible. If it were me I would work on general commands until hunting season. If you are struggling getting the dog to respond to sit, stay, etc... Trade him for another. Once the season starts take him on a leash on every recovery you can. I would find the deer first without the dog then take him on the trail after. You should make sure his first few trails end at a dead deer.
Reward him when you find the deer no matter if it had anything to do with finding the animal. It is so important to expose him to real trails. After a few he should start to "look for the deer". If he gets on trails that are not from a wounded animal Stop him immediately. Myself and a few friends have tried, but just haven't had the results we were looking for. Mainly because we did not put the dogs on enough trails.
Willow Point use to offer blood training and they got results, because your dog would be paired with a great blood dog and get to track every day. It was expensive. I never used this service, but the guides swear-ed it worked. All of their dogs were great. Good luck