Training your dog to come reliably when called is extremely important, you never know when you will need to protect your dog and the best way will be to call him back to you. Especially, if like me, you take your dog out to parks where you do not have to leash your dog.
I started training my dogs when they were puppies in the safety of our house. I made a big deal out of getting a treat, so the dogs knew I had one, then I called Sadie and Rusty. When they ran over, I gave them a treat and a lot of verbal praise.
Once Sadie and Rusty would come to me in the house, I moved to the back yard. The yard provided more distractions and a new environment while still keeping things safe. I would have a treat in my pocket, I would call Sadie and Rusty to me, when they came I would give them the treat and verbal praise.
The final step was to have my husband and I take a field trip to the dog park. The park is full of distractions, strangers and opportunities for puppy mischief. Using leashes Chris, my husband, would walk Sadie and Rusty about fifty feet away from me. Keeping a close eye on the dogs, Chris would have the dog’s sit and unhook the leashes. Then I would call for the dog’s to come and when they did, I would praise and reward them. Then Chris would call them back. It’s a great game for exercising the dogs while teaching them to come. You can increase the distance from your partner as your dog becomes more reliable.
Now both Sadie and Rusty come when called, I do not always have a treat, but because they know the command they respond even if distracted. I do give them a treat at a minimum every 3-4 times to reinforce their good behavior.
Make sure when you are working with your dog, when you call your dog you are giving them a treat or doing something they consider fun. If you call him and reprimand him, he is going to associate coming to you with an unpleasant consequence and stop coming when you call him.
Food and praise motivates most dogs, so when they come to you make sure you give a reward. I may not always give my dogs a treat, but I always give them praise and pet them immediately to reinforce their good behavior.