We stop (a really sudden stop), as soon as the dog moves ahead of us where she loses us from her peripheral vision. And when we stop, she has to go back and sit beside us, and look us in the eye for direction. As soon as she looks us in the eye, we decide where we will go.
Or we will make a 180, and turn into the opposite direction without warning (usually when she walks too far ahead of us before the leash gets tight. If she turns when we do before there's a snap in the leash, she gets a love party and a treat.
These techniques would depend on the amount of time we have available for the walk. But during training walks, we will use the 180 as preferred method, since it gives our 95lbs dog the opportunity to really learn that we are the ones who decide where we are going.
Also, but not immediately related to the walk in practical sense, is having the dog leashed to you in the house, and expecting the dog to go where you go. You need to go to the kitchen, dog has to come too. You need to sit on the couch, dog needs to settle down too. Etc. It tells the dog that YOU are in charge and decide where things are happening, rather than the dog deciding what's next.