Organise that equipment before the performance

Always organise any equipment well before the big day. String players should carry extra strings. Don't forget shoulder-rests, rosin, or other equipment. Keep a screwdriver in wind or brass instrument cases. Wind-players should take their pull-through or swab into the examination room; it is acceptable to take a few moments to clean out between longer pieces. Pianists should not hesitate to adjust the piano stool to a comfortable height, or to ask for another chair. Reed-players should start “blowing-in” reeds weeks beforehand to have several spare ones in case your tried and trusty reed packs it in.
(Excerpt from "Confident Music Performance" by Ruth Bonetti. Available at www.RuthBonetti.com )