My newly adopted dog is a loving dog, licking my hand all the time. I used to this in was the last, but the internet says this is a sign of affection. What's the truth?- Leonard
Firstly, licking is generally seen as a gesture of social solicitation and appeasement. Think of baby pups licking their mom's and vice versa. Many people are perfectly fine with dogs licking them.
However, I assume you don't want this to become something that verges on compulsive. In which case, teach sit, down, and hand targeting as a way of redirecting your dog's attention to something else while still engaging socially with him.
Sit and down can be taught by holding a tiny piece of food at your dog's nose. Lift your hand very slightly up and back towards your dog's rear so his head goes up and his rear goes down to follow the food lure. Say "yes!" when he sits and give him the tiny treat. Repeat this until he is smoothly following your hand into the sit position. At this point you know you can get the behavior of sitting, so say the word "sit" right before you move your hand, say "yes!" when he sits and give the tiny treat.
For down, once your dog is seated, move your hand slowly to the ground and slightly in and towards his chest. He will follow the treat to the ground and slide into the down position. Say "yes!" and give the tiny treat. Once he is moving smoothly into a down by following your hand, say "down" right before you do so, say "yes!" when he is lying down, and give him the tiny treat.
For hand targeting, it is about teaching your dog to touch his nose to the palm of your hand. This is useful for redirection, but is also the basis of come when called. With practice, you should be able to show him the palm of your hand and say 'here' or 'touch' and have him run to your hand even from a good distance away. Start by showing him your open palm placed about 6 inches away. He is likely to touch it with his nose out of curiosity. Say "yes!" and give him a tiny treat. Repeat many times in 3-5 minute training sessions, gradually increasing the distance your hand is away from him.
Pretty soon, he should be zipping towards your palm in order to touch it with his nose!