Hi, I also wish you good luck. Although I find this course great I'd encourage you to take also one they offer about Relationship. I had one by Mark Keating "Relationship games", which the dogs (and I) loved so much. It really helps so much strenghtening the bond with you and would be of great value if the owners learned something like that too. It has first to be trained in a distraction poor region, preferably at home, if someone has a bit of space.
I know it doesn't sound much about walking, but realationship building is preliminary and should then be kept on for the rest of the dog's life. Once soemthing is engrained it can easily be combined with walks and is especially worthful if we use such exercises to keep the dog's focus on us within distractions.
Also "Teaching Engagment Skills" by Forrest MIcke is a very recommendable course in this direction. He shows how to keep the dog's focus on walks and on spots with more distractions
With all this I of course don't mean at all you should leave walking for the moment, on the contrary. Walking is one of the most important and interesting things for them. Just meant as a very helpful complement and support..