A good audience is your reward for practising. So you like them and then they will probably like you. All the previous advice is good. The audience is always more likely to enjoy what you do if you enjoy it yourself and show your enjoyment in it. It is always worth remembering that the audience is very often more nervous than you are at the beginning. That is why I often deflate the tension as soon as I can, by saying something to make them smile.
I would add that I like to have everything laid out where I can put my hands on it without even thinking. I know where my flat picks are, my harmonicas, my thumb picks and my capo. Being able to reach things easily helps you to project an aura of assurance.