GOAL SETTING:
Think about setting a goal (say - making it to the sidewalk) and ANY time your dog leaves the heel position, before you get to your goal...go ALLLLLL the way back to where you started and try again.
Lather, rinse, repeat until you can make your goal.
How many turns did it take?
How long did it take?
15 minutes? 30 minutes?
Great!!! You just took a 15 to 30 minute walk.
If you have time, and you want to go further, great! Set a new goal and do the same thing.
If you're out of time, that's still ok, because you've already taken the same amount of steps you WOULD've taken on a 'pulling/non-heeling' walk!
Keep in mind: EVERY time you let your dog go somewhere out of the heel position, you're telling the dog he doesn't have to heel. So, if that's been happening, time to go back to the drawing board and repeat the lesson that if the dog wants to advance in space, it must be in the heel position.