Find one day a week to initiate a day of vocal rest. This means no talking, singing or any noise whatsoever. Professional vocalists will use this rest period to let the vocal chords heal.
Drink plenty of liquids such as tea with honey. The warm tea will help to lubricate your throat and warm it for singing. The honey will help to soothe and coat your vocal chords, making them more responsive and less prone to injury.
Warm up properly before any vocal exercise, concert or practice routine. A proper warm-up will head off a lot of potential damage. Buzz the first five notes of a major scale with your lips to warm up your voice and then sing scales at a medium volume.
Avoid smoking and drinking, as both of these activities will dry out your vocal chords, making them less pliable and more susceptible to vocal damage. Find ways to avoid breathing in heavily polluted areas.
Drink water instead of coughing or attempting to clear your throat. When you clear your throat the vocal cords rub together causing irritation. Blow your nose often when you are sick.
Avoid screaming, yelling and crying as much as possible. All of these activities will strain your vocal chords and cause your voice to weaken.