I was given Zody when he was a year and a month old. By the time I got him he was already on the road to reactivity, I knew that, but I had no idea just how bad he was until he and I moved into a 4 plex apartment 5 months later. You see Reactivity to people really doesn't manifest when the dog is way out in the country with minimal exposure to people, or when he's in a very quiet neighborhood again with limited people. Move to an apartment complex and it's a completely different story.
At the apartment complex there's people, all sorts of people, and they can appear out of nowhere. Zody didn't appreciate that and he became a barking, pulling, lunging, monster. I knew he was reactive, I just didn't know he was that reactive. I learned that quick fixes are just bandaides. They do not really do much but mask the problem. The higher value the treat or reward the better, but watch the calories. Patience is needed, Zody is fearful, and needs help and understanding, he's not not trying to embarrass me nor is he bad. Don't be afraid to end the walk early, it's best to do that rather then fight through and have it get worse.
To help him I use a pocketful of treats, like I said I watch the calories in the treats I use or he gets fat. He sees a person he gets treats. In the beginning I had to stay far away and be on high alert all the time, because it really helps to give him the treats as soon as he sees the person and before he has time to start barking. No cue is needed, just he sees the person he gets the treat. Slowly we started to get closer to people, and he began looking at me for his treat when he spotted them. I knew we were really getting somewhere when he began to stop reacting to the people he really disliked (they used to be neighbors and walked past HIS window), there came a day he didn't bark, and now he'll greet them since I give them treats to give him, yesterday he let the lady pet him. I had a friend comment today that Zody wasn't barking at him even though he was only around 5 feet from him, in the past Zody would have been actively trying to chase him off. Again, it was slow, it took months to years, depending on the person. He's taught me to respect the distance he needs to be comfortable, and to maintain a bit of distance even if he's not reacting. I can't be stingy with the treats, and using high value ones is important. When he's uncomfortable we leave, and he gets treats as we are leaving. I learned that if I give people treats for to give him to tell them to drop the treats, and not touch him, or if he's really comfortable they get to hand feed but not touch his head. He does not, and should not, be made to do any special behavior before getting the treat, he gets the treat when he sees the person, simple as that. I do not cue him to sit, look at me, come, or any other behavior.
He's doing better but he's not perfect, he does still have bad days, he does still bark, those are the days we cut the walk short. Success is measured in steps, not feet. When we started he had maybe 5 people that he would let near him, now he has many people that he's actually happy to see, and a few of those people are ones I thought we'd be doing good to simply get him to stop barking at. He may never be completely good with all people, but I'm proud of how far my boy has come, and happy that I did not give up when we were still taking 5 steps back for every step we took forward.
To those with reactive dogs, don't give up! If you need professional help, find it but make sure they are using DS/CC and not anything else, I can post some links that really helped me with Zody. If nothing seems to be working ask about medicine, sometimes it's necessary. Zody's not on any for his reactivity but does get anti anxiety medicine for his thunder phobia, without it I cannot work with him on that fear at all and he makes himself physically sick from the fear and stress.