Let's talk about actions to avoid in order not to harm your singing voice, as well as some actions that should become part of your daily habits, so as to work towards a healthy set of vocals!
THROAT CLEARING OR HARSH COUGHING
Clearing your throat whenever we have phlegm or mucus is a very natural thing to do. However, whenever you clear your throat, what you're doing is 'rubbing' your vocal cords harshly with each other, and this could cause unnecessary injury to your voice!
Coughing harshly and loudly also brings great tension and strain to your voice, because the loud sound is created by your vocal cords squeezing tightly with each other, and this also can cause unnecessary damage to your singing voice.
What you should do here is to clear your throats by producing a gentle cough where there is lots of air used but little sound produced. This can be done by breathing in and taking in air and then expelling it with a silent 'H' sound, creating a low rumbling sound with your vocal cords.
SMOKING
Apart from the fact that Smoking is bad for your heart, lung and vocal tract, it is also disastrous for your singing voice! Smoking tobacco irritates and dries the vocal tract and causes irritation in your throat, which will usually make you clear your throat more regularly and cause unnecessary tension and damage to your vocal cords.
YELLING OR TALKING OVER NOISE OR MUSIC
When you're hanging out in the club, at a party or in any other noisy place, you probably yell or try to project your voice over and above the general noise level of your environment. This is not good, because it subjects your vocal cords to intense tension and strain, especially when you have to talk extremely loudly for long periods of time in those noisy surroundings!
A good voice protection tip would be to reduce your speaking time in noisy environments or perhaps just talk less and in shorter sentences, so as to avoid too much vocal abuse. You can also move closer to the person you are talking to and talk in that person's ear rather than yelling.
EXCESSIVE PHYSICAL FATIGUE
Talking when we are excessively tired or exhausted is certainly not a very good idea, and will subject your vocal cords to unnecessary strain and stress
You should rest and make sure that you have sufficient energy and are conscious and in control of our actions, before we begin to talk and communicate with others. Doing some simple stretching exercises for your neck, shoulders and for your body in general before singing also will help you relax and be stress-free, and also keep your voices healthy!
BREATHING THROUGH THE NOSE
When the weather is dry and harsh or even dusty, particularly during the harmattan, your throat feels dry and irritable. You should try and breathe through your nose and not through your mouth.
This is because when you breathe through your nose, the air goes through a natural filter which will not only remove most of the unnecessary particles in the air, but this air will also be moistened as it moves through your nose and progresses through your throats to your lungs. This makes the air less dry and reduces the 'drying' effect that it could have on your vocal cords and throat.
When you are singing however, you should prepare a glass of lukewarm or room temperature water to moisten your voice and throat now and then, in order to avoid excessive dryness and irritation
These are some of the Voice Protection Tips and Techniques that i have gathered mostly through personal experience and training sessions. I believe if you apply them properly, it will definitely help you.