Recognizing that dogs are living, breathing creatures, they need to have fun. If the dog only ever sees you for training, you are missing a big part of the relationship.
Take your dog out and let him run, play with toys, lay in the sun, take a break, and just be a dog. It will make for a happy dog that wants to please you by doing the right thing when training. In a strong dog team, the dog's desire to please the handler provides as much motivation as the toy or the treat.
My first dog was not especially affectionate, and I wouldn't say that he ever loved me in the way that a pet loves its owner. He had handlers before me, and he would have more after me, but we still had a strong bond, which made us an effective team.
I took him out, let him play, tossed a ball for him, let him lay in the sun, and took him for long walks with no commands. He knew when it was time to work and when it was time to play, and he trusted that if he did what I asked and made me happy, good things would come to him.