1. Stay hydrated:
Make sure to drink plenty of water to keep your vocal cords refreshed. If you’re going to be drinking water during your recording session, drink room temperature water. Cold water can shock the vocal cords and create tension which can temporarily limit your vocal range. It constricts the muscles in your throat, which causes loss of flexibility. Proper hydration keeps your vocal cords lubricated.

2. Get a good amount of sleep:
It is important to at least get 7-9 hours of sleep. The amount of sleep you get effects your overall health, which effects your vocals. Your body, like any machine, can be overworked and develop problems. Each day, take moments for vocal rest. And try not to speak when you’re sick. Illness puts extra stress on your voice.

3. Keep warm:
If you are outside in the cold, wear a warm scarf around your throat and chest area. Breathing in cold and dry air can irritate your throat.

4. Steam Breathing:
This is the process of breathing in steam to soothe and open up your nasal passages when you have a cold or sinus infection. The warm moist air helps to loosen mucus and relive cold symptoms. You can breath in steam from a pan or kettle on the stove, or you can take a hot shower and breath in the steam, letting the hot water hit the sinus and larynx areas. You can also use a humidifier to humidify whatever room you’re in. Overall, moist is good for the voice.

5. No smoking:
Having healthy lungs is essential for good breath support, which can effect your overall vocal range.

 

6. Protect Your Voice:
a.) Just like stretching before a dance routine, it's important to warm up with vocal exercises, of which many examples can be found for free on websites like YouTube. Here's an example: try singing "ah" following along with the music notes of this video below:
www.youtube.com/watch?v=fCxmDUl8__U
b.) Doing "tongue twisters" can help to loosen your mouth and improve your articulation. Example: Say "Irish wristwatch" 5 times at a fast pace and spoken clearly. A few other examples: Unique New York, 
c.) To further avoid vocal strain, It is best to avoid yelling and screaming if at all possible. And contrary to popular belief, when you are sick and have a sore throat, the worst thing you could do is whisper. This will have the opposite effect of preserving your voice. Whispering actually strains the vocals, so it is best to go on complete vocal rest when needed. The extreme ends of your vocal range put stress on your voice.
d.) Another thing to remember is to relax your throat when speaking or singing. Depending on the sound you’re trying to create, you may be tempted to tilt your head up or down (example: lifting your head up to hit a high note when you sing). This can strain your vocal muscles and possibly limit your vocal range in the future. A better option would be to raise your eyebrows.
e.) Make sure you are using your diaphragm muscle when performing, which will greatly reduce any vocal damage.
f.) Do not clear your throat too often. When you do this, it's like slamming your vocal cords together. Doing it too much can injure you. Try a sip of water or swallow to quench that urge. If you feel like you have to clear your throat a lot, get checked by a doctor for possible acid reflux disease, allergies, or sinus conditions.

7. Watch Your Food Intake:
On the days that you plan on recording, try to limit or avoid consumption of:
• Caffeine (this can sometimes dry out your throat and larynx)
• Spicy Foods (can lead to acid reflux in your esophagus which can possibly burn your vocal cords)
• Dairy Products (milk, yogurt, cheese, butter, etc... dairy tends to cling to your throat while thickening the mucus that is already there)
• Alcohol (irritates the mucous membranes that line the throat)
• Fried Foods (anything that has been deep-fried or prepared in a lot of oil tends to gunk up your vocal cords with too much fat)
• Processed Sugar
• Chocolate
• Soda
(I do recommend that you eat SOMETHING before a session to avoid any tummy rumbles when recording. Consider eating whole grains, fruits, and veggies. They’re great sources of vitamins A E and C and can help maintain those mucus membranes lining your throat)

Consider consuming:
• Non-acidic fruit: Mangos, strawberries, blueberries, raspberries, apples, grapes, and plums)
• Fruits with a high water content: Pears, watermelon, peaches, apples, grapes, and plums).
• Vitamin A rich foods: Vitamin A helps keep your mucus membranes nice and healthy. It can be found in yellow veggies like sweet potato and squash, fruit like mangos, peaches, and melons, and dark leafy greens like spinach and kale. Eggs and meat are also great sources of both Vitamin A and protein.
• Protein: A healthy voice requires a strong body with generally good muscle tone and endurance, so protein can help build that muscle. Eating foods like chicken, fish, unsalted nuts, and honey (which helps soothe and coat the throat).

8. Take Care of Yourself:
Your voice is tied to your overall health. It’s all connected! Exercising increases stamina which increases muscle tone which can help to improve your breath support. So exercise and eat healthy!