Why doesn't your dog follow you on walks? Most likely, you're not exciting him enough! YOU should be the most exciting thing.
To start out, ask yourself some questions about yourself:
1) What do you go out on walks for? Groceries, window shopping, meeting friends?
2) What are the different walking paces for these different walks?
3) What are your favorite things to notice on your walks? Stylish people, other dogs, woman/men?
4) What do you try to avoid outside? Strangers, bad smells, trucks?
Now, 'ask' your dog the same questions (that means observe or try to guess). Some answers he could possibly give are:
1) I go outside to: go to the bathroom, meet other dogs, meet people, exercise, or even - I don't know why my owner takes me out, I hate going outside!
2) I walk at different paces when: I have to go to the bathroom, I know where I'm going, I don't know where I'm going, when I'm running away from dogs, people or children etc.
3) My favorite things to notice are: leaves on the ground, chicken bones, my owner, sharp movements
4) I avoid: Trucks, loud sounds, crowds, other dogs
Now that you're aware of both of you and your dogs motivations, you probably have a better idea of when it's best to train together - when you both have time, AND when you can avoid things that might distract both of you
Now for the fun part! YOU are going to become the funnest most exciting part of your dog's walk:
Practice at home first becoming the apple of your dog's eye while not on a leash: what gets your dogs attention? Running, balls, treats? Excite your dog enough to follow you in any direction; circles, squares, backwards forwards, running, slowly...You'll notice that just by changing your pace your dog's attention is always on you! And, always reward for good responses.
Tip: If you are having trouble getting your dog to move forward, try bending your knees while stepping forward to make the whole movement very obvious
Now, add a leash inside and continue to be the apple of your dog's eye, rewarding him when he follows your every move. And, don't forget to encourage with your voice!
Practice outside without other dogs around, and always reward for good behavior!
Now practice with distractions one at a time - leaves, shopping, trucks, dogs - refer to your list!