Great suggestions here: know your music, audio recordings, video recordings, stack the deck, etc. A few additional thoughts: 1. Practice like you want to perform. With an iPad or without, with charts or without, plugged in with a mic, monitor or in-ears or not, etc. Try to minimize what's new besides the venue and audience. 2. Baby step: Invite a few friends over for beers or dinner and a small house concert. Play a few tunes. 3. Next baby step: Hit an open mic night or two with your one best tune. Then with go do it again with 2-3 tunes. etc. At the end of the day the hardest thing to achieve is a sense of pride and well-being for where you are as an artist today, while striving to be a little better tomorrow. Good luck!