one of the things that I learned while taking college leveled vocal lessons (which seems really gross) is to swallow mucous instead of spitting it out. This gives the cords an added moisture protection. Another things that we so often overlook is water. Drinking water helps our natural body to maintain that needed level of hydration. Make sure the water is lukewarm if taken before or during performance. Oh, yes, don't forget that a warm-up is a must. You can't really expect the cords to move properly without an exercise. Would you workout, or do a cross country relay without a warm up?
Grace & Peace,
Mondi