The most difficult concept for me to learn about performing was that I could (and should!) talk to the audience. Naturally, they come to hear the music; but they are also interested in such things as brief tidbits concerning the song's history or what it is about the song that appeals to me (why I choose to sing it). I was surprised to discover this latter item as being of anyone's interest but my own. Once I learned to speak to my audience, share a little with them, and, as mentioned above, to be human with them, the rest seems to have simply fallen into place. A good way to get feedback is to make yourself accessible after the performance and to listen to what people from the audience have to say about your "show".