I think it's good to associate it as much as possible with good things - carrying treats to mark her good behavior, then keep you in front of your dog/away from them and keep walking.
I utilize the small dog as a training tool (a distraction). I'll pretend that I'm totally ignoring the small threat, while asking my dog to either do something different (Look!) or if my dog is reacting, then I'll ask my dog to continue walking forward, rewarding when my dog focuses on me and not the small threat. I do not ask my dog to sit, or stay. I want to remove him from the distraction.
I'll sweep out a leg and kick the dog, or shove it, or what ever it takes to keep it off my dog. But I try not to let my dog see ME react to the other dog. My reaction to the threat will dictate how my dog reacts. If I start screaming or scolding or shouting, it will cause my dog to react. I want my dog to ignore.
A bigger dog will cause a different reaction from me. That all depends on the size of the threat to my dog. If I don't feel I can safely ignore the dog and utilize the distraction as a training tool, then I will go into defense mode.
My focus and my responsibility is for my dog. I don't worry about what other folks will think, or if I make Suzie Dog Walker mad because I kicked her dog. I won't engage in a shouting match with the owner. If I do, I'm teaching my dog NOT to ignore but to react.