Horrible Singing : Misconceptions, Misguided Notions About The Way To Sing Good
1."Sing constantly to develop a good singing voice." It is correct that singers need a large amount of practice, maybe way more than other musicians because they're building their instrument--their voice--while playing it. Your throat muscles, sense of control, and range all increase in power as you practice, so singing practice is certainly a great thing.
However , even the best vocalists need to take a day a week off, and you should ensure that you do not sing for longer than what's comfortable. Continuously work up to a few hours a day, if singing is your profession, less if it's's a hobby, but do not go direct from never practicing to consistently practicing, and do not forget to take frequent breaks and days off.
2."Singing should hurt, that is your muscles being built." In actual fact discomfort is your body's way of telling you to stop doing whatever you are doing. If you're experiencing discomfort while you're singing, something is wrong. Don't continue to sing in that way or you'll ruin your voice. Find a good, reputable singing teacher and get to the center of your problem, but under no circumstances should you just keep singing.
3."Techniques like vibrato and crossing a vocal break will come naturally." Sadly, this just is not a good singing tip. Both vibrato and the power to cross breaks takes a large amount of difficult work, and an experience of the techniques behind each. It is true that you will doubtless not notice your vibrato developing until it's full and rich, and you may not notice your ability to cross vocal breaks until singing a certain challenging song, but they're not automatic techniques.
4."Singing with vibrato will hurt your voice." If your vibrato is carefully controlled, this isn't true. Singers of the "vibrato is bad" discipline frequently can't produce the effect, and claim that vibrato in the vocal cords is equivalent to the vibrato effect on a guitar or other stringed instrument. Those instruments, they say, steadily go de-tuned, so think of what's happening to your vocal cords when you sing with vibrato!