How can leash training be hard? You go for a walk with your dog, enjoyable for both of you….and yet….
Don’t leash train your dog, teach him to want to be next to you. Start by taking your dog outside and playing until your dog is relaxed and a somewhat tired. Go in the house with no distractions. Take a little piece of treat and take a couple of steps forward and give him the treat, at your side. Take another couple of steps and treat again. Start walking around the house with the treat at your side and your dog following at your side. Randomly give a treat. When he’s making turns with you and staying at your side, add the word “side” and continue to walk.
Put a leash on your dog and do as above but let the leash hang loosely, no pressure. When this is mastered, do the same thing in the backyard. Remember, loose leash. Then a short walk in the front yard. Loose leash and make sure your dog is paying attention to only you.
Do not introduce your dog to another dog until the loose leash walking is perfected. If there’s a slip up, go back to the front yard or the backyard or inside the house if you need to. Remember to talk to the dog. Give him encouragement. If you’re away from the house and there’s a slip up and your dog is pulling toward another dog, turn around and go the other way, talking happily and walking jauntily as you go.