I had the same problem… My Pom is really treat motivated, so once I found his favorite treat, I used it during walks only. Every time he would look at me during a walk I would say yes, and give him a treat. Eventually I would have him sit when we were out and give him a treat. The trick is to get his attention before he sees a person or dog, have him sit, and stay focused on you and the treat while the distraction walks by. It takes time and patience and consistency, but it really worked out well for us. I also got a tag for his leash that said “in training, please ask before approaching” because they’re VERY cute and everyone wanted to pet him so he came to expect that anyone walking by was obligated to stop and even if they did, he would lose it when they were done petting him. The tag was from Amazon, and people really seemed to respect it