Also, use people's names, not excessively though, that's a recipe for disaster.
I try very hard to remember their names, even if I am unlikely to see them ever again, such as when seated at a table for a show. If you remember their name, they feel they had your attention. I say their name three times right then and there by saying "Nice to meet you Joe. I have found that if I repeat a name three times when I meet someone, Joe, that I will remember that name the next time we meet. So, Joe, enjoy the show."
I love that be the first person to say hello method. I am going to use that one.
I was taught to be wary of others, and I believe that puts people ill-at-ease. So now I try to feel joy when I meet and converse with just about anyone. We both enjoy the meeting much more, and I am better able to make eye contact.
I think you're on the right track with the name thing, just that alone will set you apart in the communication and will be remembered well. If you were to see that person down the track and remembered again I think they'd be impressed.
I liked your last lines; being wary is not a bad thing, but a smile and genuine greeting goes a long way.
Another good thing to do - pet their dogs and learn their dogs' names.
For sure, I do this a lot on business dealings. It's powerful.