Nil illegitimum carborundum. Listen to yourself and to friendly criticism, and be aware that some sods are jealous. Always think of how you could do it better, make the songs your own and not just an attempt to reproduce someone else's performance. The rules of appropriateness apply- match the song and delivery to the audience. If you want to sing a particular way, save it for people who will appreciate that way.

Do as I say, not as I do.