Yes, I do train my dogs. I hate it when I see unruly dogs just the way you do. I do not like dogs that try to growl and try to bite mine when I take her to the park. I have trained her from the time she was very little. She will always heed my commands. This is very rewarding for me and easy on her.
An untrained dog is a confused dog. He does not know that he is not the one in control. "You need to be the pack leader of your dogs" that is what my father used to tell me. "You command and they obey".. this has helped me with all the dogs I have had. Once trained we have an easy relationship and enjoy each others company at ease.
My dog knows, sit, stand, heel, stop, go, fetch etc., She is very sweet and obedient by nature and it was a pleasure to train her.