Write down the horn lines and horn harmonies for the most common tunes in the recorded key and the most commonly played keys... if you hear something like Amy Winehouse on the radio, you may as well right it down, too, cuz you're gonna have to learn it. Bring back up percussion... I bring shakers, a tambourine and claves; I'm about to get a pair of bongos and a cymbal stand for them. It helps to have something to do when there are no horns. What I've found is that the whole horn section loots the stuff I bring to use during the show, hence the added bongos, but really, any little thing will do, just so you're not standing around doing nothing. Learn to do a little two-step: you don't have to be a great dancer, I can't dance to save my life, but you have to look like you're having fun on stage. it's such a buzz kill to work with guys who just stand there and stare at their mic. Also, pic up one of those "sound-mirror" things... I'm used to playing with loud bands, so I haven't gotten around to picking one up yet, but it's on the list of things to do. NEVER rely on your monitors. Especially on flute! Get a piece of plexiglass in case you have to play outside. It beats the hell out of clips. No matter what, always show up with a mic, mic stand, cable, XLR/Quarter inch adaptor, music stand, stand light, and horn stands, even if you don't think you'll need them... you can always leave them in the car, but if you need them, you'll NEED them. I keep one bag packed and ready to go most of the time with as much stuff as I can fit in it, so I can save the scrambling around for my gear. If I take anything out of the bag at home, i just leave it open, so I'll know to check everything. Just some tricks I've learned, and many that others have learned for me. You don't want to come up short on a gig, so better safe than sorry, I say.