Since I am currently delivering pizzas for a living I have on occasion encountered unfriendly dogs. This morning I was walking down the street to Aldrich's Market when I passed by a dog and it barked and scratched me on the leg (no blood). Good thing his owner had him on a leash because it could have become a much worse. I think it must have been too much eye contact, but I'm not sure.
So naturally I googled to find an answer. I started with horses oddly enough because I had a roommate some years back who applied some ideas from a horse whisperer guy on using predatory hand signals to training his dog. I thought if there was something about the posturing and signaling of predators then I might figure out what I did wrong. Natural horsemanship is really cool but none of the videos I found talked about how to use predator signals.
So I then went into dog stuff. Here's the best video I found on the subject of preventing dog bites: