Always sing standing up. Stand up straight, shoulders back, chest lifted up out of the pelvis, and don't stick your chin out or up.
Always sing full voice. This doesn’t mean to belt everything, but sing as loud as you comfortably can. This builds vocal strength.
Always warm up for 10-15 minutes before you sing your songs. If you have a recording of your lesson, the warm-ups there will be sufficient. If you do not have a recording, you can make up any warm ups you like, but remember to always begin and end every exercise in the middle of your range, where it’s comfortable.
Watch yourself in a mirror as you practice. This reinforces much of what is said to you in a class about posture and relaxation and quickly eliminates awkward physical ticks and positions.
Don’t practice more than 30 minutes at a time for awhile after starting lessons. It’s okay to do this more than once a day, if there is a good space between sessions, but your voice is like any muscle you exercise and strenuous workouts must be worked up to gradually. As you get used to the workout, you can increase the time.
If your throat starts to feel uncomfortable in any way, stop singing. Your throat won’t let you know you’ve hurt it till the damage has already been done, so if it starts to feel sore or achy, stop singing immediately and rest.
The feeling of what you are doing is more important than the sound, so don’t become a critic of your voice on a recording.
The more you sing, the more you will sound like a singer. This seems self-evident, but the difference between the voice of someone who sings once a week and the voice of someone who sings everyday is remarkable. You gain maturity, strength, and control by singing often. I know everyone is busy, and I tell people that practicing four times a week is a good average, but remember that you set your own pace of growth by how often you practice.
If you vocalize for a half an hour everyday, you'll be surprised at how ready to sing you'll always be.
Always warm up one or two notes higher than required in your performances. Knowing that you can hit those notes will allow you to feel more comfortable about the ones that ARE required in your performances.
If you have to cough or clear your throat, do so gently. These actions are like sandpaper to your vocal cords.
Be sure your shoulders don't rise when taking a breath. Remember, the audience wants to think it happens by magic.
Tension is bad for good singing, especially in the jaw. Stand up straight, then let go of muscles that aren't part of the singing process.
To help prevent or reduce the effect of aging on the voice, try using your voice more - those with a trained singing or public speaking background often have stronger voices as they age.
Don't smoke. Smoking puts your entire vocal mechanism at risk. Also it accelerates the voice changes associated with aging.
Don't try to imitate another singer's voice. Your audience wants to hear YOU.