Our dog has an issue with other dogs ONLY when she's on a leash. That has been our mission. To deal with this lunging, barking, growling, idiotic behaviour. We've had pretty limited success until recently. Something shifted in MY attitude, and instead of inwardly thinking "oh, no, a person with a dog, here we go..." I've been heading out with the full intention of FINDING other people walking their dogs so that I can work on correcting bad behaviour. Now I'm seeing that as a challenge, and I even went so far as to take her to our equivalent of a dog park and walked her around on a leash for a while before she earned free play time.
We have made SO MUCH progress in just a few days, I can't believe it. She still gets that "look" and once she still slipped into lunge/growl mode, but with just a few leash corrections and pulling up on the leash to put her back into a sit snapped her out of it. Whenever she starts getting "antsy", I just pull up, and she sits, and we wait until she calms down, then keep going. If she won't respond to that simple request, then I keep the upwards tension on the leash until she "chills", or breaks her stare and looks at me instead.
We even walked by our neighbours dogs (behind their fence, barking) with our dog on leash, which usually causes her to completely freak out. She got a little excited, I gave her a leash pop, and she looked away from them and continued walking with me. YAY!!!
Let's hope the progress continues, and that I'm not seeing a temporary aberration! I think the big thing is MY attitude. I have always tried to give the impression of calm and assertive, but that little inner voice was often harboring doubt. Now that I'm not worrying so much about what others think, or the impression our dog is giving them, HER behaviour seems to have responded as well. It's true, I guess. We can't lie to our dogs!

But the good news is, now that I have gained confidence, and am truly determined to erradicate this rude behaviour in our dog, she's responding, which boosts my confidence, which boosts her confidence... see where this is going?
Thanks for letting me share! Wish us luck that this improvement continues!