The most common way I communicate with my blind/deaf dogs is with my hands. I do give certain cues with my feet because it is easier for me than bending or because it blends more perfectly into the exercise we are doing. But for the main part, I use my hands. I will also use my body to convey to my dogs which direction I'm going and how quickly by brushing past them lightly. My dogs have learned to read my body and know whether I am standing up, sitting in a chair, lying down, etc.
I use my breath for waking my dogs while they are sleeping and for calling them to come to me from across the room, for instance. They will notice me blowing in their direction and will come to me or are able to wake up more gently than if I startled them awake with a sudden touch.
My dogs know a lot of cues. It can be challenging sometimes to find different places and ways to touch the dog's body that aren't too similar to other touches. But with consistency and patience, you can teach your dog many, many cues, even some that are similar to each other. There are times, though, that my dog may do a different behavior than what I asked. I don't ever get angry. It was probably because I wasn't clear in how I gave the cue. I just ask again while being intentional to be as clear as possible.
It's important to use any equipment (collar, harness, leash) very gently with your dog. Equipment used harshly can cause physical damage to your dog, and can cause him/her to be stressed about training time. Even with a loose leash, my dogs can tell when I change direction, stop and speed up or slow down.
Dogs are sensitive enough to notice a fly landing on them - they don't need to be yanked harshly. By using consistent and gentle guidance with their equipment, you can teach very subtle cues for stop, start, left, right, etc. This will help your walks to be more enjoyable for both you and your dog, and will allow you to keep your dog safer by preventing him/her from bumping into things or falling off a curb.
Here's a little video that shows some of the basic touch cues I use: