A mistake I never made. I always looped my guitar lead, something that occured to me one late night playing (cough) with myself, if you will.
Something that didn't go wrong, but very nearly could have was:-
My band (much to my own disapproval) play alot of more "popier" songs...okay, so we play nothing but and we landed this exposiour (?!) gig with talent scouts, etc. The problem was, all the other bands were playing stuff like Limb Bizkit, Rage, y'get the picture. This led to our singer (female, younger and extremely shy) beginning to panic, after attempts by myself, fellow guitars and drummer to calm her nerves, we found ourselves with a worring bass player. Quickly followed by said fellow guitars. It wasn't until a band played Bob Marley that they relaxed and everything seemed to be alright...But then it was my turn to panic! Hands shaking, trying to set up my FX pedal, getting endless feedback because someone had turned the amp up to 10 (not good with compious amount of distorstion). Fortunatly, this tale has a happy ending. The crowd went off when we played the first song (knocking over two mointers and scaring the singer, hehe). Just goes to show, sometimes things work out and you never had anything to worry about!