Even if you have a large, fenced-in, private property, all dogs need to learn to walk on a leash. This is not about training your puppy to “heel” or not to pull, or to walk at your side and sit when you stop walking. Yes, all of that is what I teach as a professional trainer for dogs. Still, right now, I only want to talk about introducing your puppy to a collar/harness and leash and helping him to learn to accept it and be comfortable with it and eventually relate it to doing something he likes. To your puppy, the leash means going out.
So, where do we begin? I always recommend starting in the house. Put the collar or harness of your choice on your puppy, and let him wear it in your home under “eyes on” supervision while you’re playing with him. Distraction is always considered a “nuisance” and disruptive when trying to train your pup. However, a trainer or pet parent introducing positive distractions can be helpful in some situations. Playing with your puppy is a beneficial distraction when teaching him to wear a collar. Squeaky toys, balls, and fetch are my favorites. Do this only for short periods of time, and if the puppy is not adjusting well or becomes annoyed with this collar or harness, remove it and try again later.
Once your puppy has adjusted well to wearing the collar or harness, maybe a day or two, attach a 6-foot, thin, lightweight, narrow leash with a small clip, small being the operative word. If you use a heavy, thick, twisted, rope-type leash, it will have a heavier clip, and a heavier clip will pull on the puppy’s neck or make a harness more uncomfortable. 
Let the puppy drag the leash around while playing fetch or other distracting activity. Periodically, hold the leash in one hand and the toy in the other hand and entice your puppy to follow you and the toy. (Squeaky toys work great for this.)
Try this, too. If the puppy is confined or if another family member can help, put the puppy’s leash on and walk him to his food bowl at mealtime. You might wonder why I don’t mention offering treats to make your puppy walk on a leash. Anyone who knows me knows I do not use, recommend, or condone the constant use of treats to bribe a dog to respond correctly. There are so many better choices depending on the activity. As a trainer, I’m OK with occasionally giving a dog a treat for good work. That said, if you prefer to give your puppy a treat to encourage walking on a leash, I will yield to your decision. It’s just not something I prefer to do. I recommend you use a happy, encouraging tone of voice, call the puppy to come with you, stop and pet him, give him belly rubs, and offer him his toy, thereby letting him know he’s doing a good job.
If the puppy is old enough to go outdoors, meaning he has been fully inoculated and your veterinarian has given the OK to take him for walks outside, you might find that the puppy will not walk very far from the front of your house. This is not unusual. I see this happen quite often. So, try this. Carry your puppy away from your home, say, half a block. Put the puppy down, and chances are, he will walk home. Take the squeaky toy outside with you and use it to encourage the puppy to walk forward.
If your puppy walks a short distance and then plops down on the sidewalk, don’t stand there trying to convince him it’s not a good idea or start laughing at how cute his antics are. Both enable him to do this even more. I have seen this in action, and trust me, it doesn’t work. If you can’t use distraction to get him up and walking, bending down on one knee at leash length is the friendliest body language you can use when training your puppy to walk or come to you. Praise him and immediately continue your walk. If all else fails, physically but gently, stand him up and restart him.
After successfully walking home, keep walking down the block in the opposite direction, and don’t stop at home. As with all training practice, do this for ten (10) to fifteen (15) minutes a few times a day.
