Stuff on their bodies
A new puppy hasn’t likely had a collar, a leash, or a small tracking type harness of any sort yet. If the pup isn’t body sensitive (ie, harness or collar doesn’t bother him) then I simply introduce it with a sniff, click, and treats routine, then put it on them.
I am still a little old school about collars: let them learn to ignore it. Harnesses are restrictive, but if it doesn’t bother them much I just leave them to adjust to wearing it while they go about their day.
But if a puppy is body sensitive, then I need to make a positive association with stuff on their bodies. So out comes a clicker, and the good treats. I’ll put the harness on, click, treat, play with a favorite toy or give them the best bully stick. Once they’ve played or chewed, I take the bully back and take off the harness.
After a minute or two, we do it again. Something on their bodies means good things, with lots of affection and toys they like. I tend to leave a lightweight tracking harness on them for longer periods at this age (8-9 wks) then I would for a companion pup. They will wear a heavier harness alot later so allowing them to adjust now makes it easier.
I prefer to lure a pup to follow a hand with a treat for a few feet, click then stop and let them have the treat. Each time the distance increases before the click and treat.
When we can walk a good ways, I will move my hand up in front of me and see if he will continue to walk on a loose leash.
If the pup is starting to look around I will lure with a treat to bring their eyes forward, click and reward with several treats. I allow a glance or short look but they need to be watching where we’re going!
A puppy will eventually pull on the leash. If it’s just to wander over there, I’ll stop and stand still. When he looks, he gets a click and has to come for his super extra killer good treat and some affection. If he doesn’t look (ohhh let me sniff that dog), I’m willing to lure the nose away, then click when his attention disengages from the too cool dog.
Then I take a step so the leash is taut again, and wait for the pup to move so it is loosened. There is a click and “rapid reinforcement”, a fancy way of saying the pup hit the jackpot with the goodies and lots of them. I will do this several times.
http://www.clickertraining.com/node/541 has a good article for preventing and correcting leash pulling.
I need the pup to stay near me, so I go to all sorts of effort to be sure they stay in a close position, their shoulders lined up with my leg and hip where they will be when the big mobility harness is on. So I lay a foundation for staying close without needing the leash if at all possible.