Thanks to toedtoes and Control_Freak, most of my approach I learned from watching, both real life meetings with animals and PBS programs on wolves and other group or pack animals. I try real hard to let dogs find me, if there is any sign of timidness or aggression I let the owner lead what I do.
I didn't know about eye contact but do try to avoid head touches.
I will say that I feel in the last ten or fifteen years, owners have been better trained at training their animals, we appreciate what you have learned. And recently we met a camper walking his very big, like St. Bernard big dog, at Three Rivers Casino in Coos Bay, OR. He and I started talking, mostly how is it living with a dog who essentially bigger than he was in a motor home. The dog was in the left side heel position but was looking from me to his owner and when I ask if I could approach the dog the gentleman nodded to me and said, "OK" to the dog and gestured to me. Well this well mannered monster was just one huge lover guy. He nuzzled and rubbed my legs with his head but never licked, just kind of smiled and was happy to greet me. He never took his eyes off his human for more than a few seconds and soon went back to the left side and laid down and closed his eyes. When we were done discussing a new campground being built a few miles away and said so long, the owner softly said his dogs name, the dog got up and they walked off.