However, do not presume that touching your dog is a lovely reward for them. In fact, touch could be aversive for some dogs. If you don't know the background of your dog and your dog generally has a bad reaction to your hand such as shying away it is a good idea to being to counter-condition and habituate it to your hands using clicker. Obviously, if your dog snaps at you when you bring your hand near this is a much more serious problem and you should call a professional behaviourist for assistance.
I learnt that petting your dog can be aversive the hard way. We had no background history on our lovely Dolly, and unthinking I went to pet her for sitting when I gave the hand signal. Unfortunately she thought I was going to hit her. Her tail went right between her legs and she cowered away, whites of her eyes staring at me, and ears back. I have never felt so terrible as I did at that moment. I had truly made my dog fear me. Not intentionally but nevertheless, Dolly was scared. I have since learned that if I go to pet her my movements must be slow and deliberate, I should not look her directly in the eyes and approach from the side instead, touching the side of her body. This way she has time to realise that I am not going to hurt her. She has already come a long way since we first got her.
When working with your newly adopted dog, there are things that could happen that might surprise you. Your dog might have strange fears that you never realised a dog could have. Just remember to always work slowly, use positive reinforcement, habituation, and counter-conditioning, and always give a lot of love and patience.