To protect your vocal cords, try these tips

• Eat Regularily and do not fast on the day of the performance
• Eat salad and increase the intake of onions (not much though) on the day of the performance
• Do not drink very hot or vey cold water as these tend effect your vocal chords
• Practice singing in the shower for added moisture
• Drink plenty of water each day
• Keep a humidifier on hand
• Limit dairy product intake on the day of your performance
• Add lemon to your water
• Use honey regularly to soothe your throat
• Practise Singing Both High And low notes to increase your range
• Reduce the intake of Coffe as it contains Caffine which is bad for vocal Chords