1. Know thy voice.

Spend quality alone time with your voice. Take your voice out on dates, so to speak, and really get to know it. You might even try recording your singing voice to hear it more objectively. Find out the answers to these questions:

Is my singing voice big or small? Thin or full?
What kind of vibrato do I have? Fast, slow, medium, heavy, thin, non-existent? Am I able to sing both with and without vibrato? When I sing without vibrato, does it feel different in my body than when I do sing with vibrato?

What is my full vocal range? What range am I most comfortable singing in?
Where is my passaggio (the pitch(es) where the voice changes registers)?
How long can I sing without taking a breath? (i.e. How well do I support my breath?) What do I notice in my body and what do I notice about my tone when I start to run out of breath?

How does it feel in my body when I am singing well and when I am not singing well?
What kinds of food and drink affect my voice negatively/positively?
How long does it take for my voice to "warm up"?

There are no right or wrong answers to these questions—everybody's voice is different. The more informed you are about your own voice, the better you will be able to care for it and improve it.

2. Take care of yourself.

Your body is your instrument and you only get one. So, stay hydrated. Get enough sleep. Don't smoke.

3. Support your breath.

You've probably heard this before by every choral director and voice teacher you've ever had—and there's a reason for that. Proper breath support is imperative if you want your tone to sound the best it can. Unfortunately, it seems like every pedagogue has a different way of explaining breath support, which leads to a lot of confusion. This is an area where a personal voice teacher will come in handy for you. He or she will work one-on-one with you to help you learn or improve your breath support so that your tone is always supported. [Read: "Choral Cliché: Support the Tone."]

4. Keep your jaw loose.

A tense jaw will cause your tone to sound constricted and may even cause you to sing out of tune. So, reduce your jaw movement to only what is necessary and don't chew on your vowels. For example, if you are singing a major scale on "ah," there is little need to move your jaw while ascending from pitch to pitch. Keep your jaw as stationary and as loose as possible, and think of making the shape of the vowel inside your mouth rather than with the muscles in your lips.

5. Read ahead of the beat.

When reading music, always have your eye at least one or two beats ahead—that way you can anticipate what's coming next and you'll be less likely to be caught off guard when you encounter a curveball interval jump. This can be especially helpful when doing a cold sightread through a new piece of music.

6. Listen louder than you sing.

Aural multi-tasking—the ability to listen to yourself while simultaneously listening to other singers and musicians in your ensemble—is a challenge that every choral singer faces. Please: Do not plug up one earlobe to be able to hear yourself better. Why? If you have to do that to hear yourself, then you aren't training yourself to listen holistically.

If you're having trouble hearing yourself in the group, one trick is to angle your music book or folder in front of you (but without completely burying yourself behind it, of course) so that some of your sound bounces back to you as you sing. Use acoustics to your advantage.

Vocal exercises will not help you like that. Most of them are to warm up the voice to prepare it for singing. Singing in a range that is not comfortable or natural to you can result in severe vocal strain or damage that may require medical intervention (like surgery) to fix, or can cause permanent damage that nothing can undo again. You may also be cracking on a particular note because you don't know how to switch into a vocal register that will allow you to sing it easily.

There are many different aspects in correct singing–all very physical and all very complicated.

If you're still in high school, I suggest very strongly that you try to get into a choir or other music program NOW. Don't wait until college. While there are college choruses that are open to any and all students who want to participate, many of the other ones are by audition only with very tough standards to get in. By college, many of those select choral groups not only require you to know "what the technical notes" are, but talso require you to sight sing. That means they just hand you a sheet of music–sometimes just random notes instead of an actual song–and tell you to start singing. Sometimes they might give you a beginning pitch but other times they expect you to just start. One reason for this requirment is that college and university choirs often do challenging pieces of music with little rehearsal time, so they can't stop to go over everything note by note. Each member would be responsible for learning the music before they even get to rehearsal. I'm also speaking of the typical college level choir–not even one associated with a performing arts school or conservatory

Just a little reality check there.

Keep in mind as well that just learning certain songs does not train you to learn to sing any other song than the one you just learned. Voice teachers will assign certain songs to their students because the songs may require the student to work on one or more techniques that will be applied to singing in general. Just picking songs you like may not do this. Voice teachers also select songs in the appropriate range for their students. Some songs may give the student practice to expand certain portions of their singing range, but again this is part of an effort to train the entire vocal range as it really is (rather than what the singer wants to be regardless of what nature gave him).

Join any school choirs and also consider community choirs and church choirs (if you go to church that is). It will give you some choral singing experience at least and hopefully some basic instruction on correct singing (more likely in school).

The exercise I use to develop my high range is to start on the pitch where I can warm up my voice. (keep in mind I am a guy and this is for my range, so you may need to adjust for your range.) Using my head voice, I will hit a B, above middle C, and first work to make sure I start cleanly, with an OU sound. If I do not get the attack correct, I work until I am satisfied with my starting note. Then I will sing down the scale in 5ths. You want to make sure you are doing this in Head Voice, not full voice. I will then run this exercise five times, moving down 1/2 step each time. After I run this, I will drop down to a B right below middle C and work to keep the same tone in my middle range. Exact same exercise. I have to work to keep the tonal quality the same here, as I have a tendency to belt out my comfortable range. Again, I do this down the scale in 1/2 steps. Then go back to your high range. For this I will start back E above middle C and do the same work only going up the scale 1/2 step until I reach the note that my throat starts to clamp down on. I identify the note that is the limit of my upper range and make a conscious effort not to go any higher than that note. With that limit note, I then will try singing the scale exercise changing OU to other voicing such as aa ee ii oo uu. If the strain is more than a discomfort, stop and work one note below.

When you start singing in your high range, if you feel any strain what so ever in your throat, don't go any higher. Drop down to the highest note that you can comfortably sing. Work on that range until you are 100% comfortable and slowly work up till you can comfortably hit the notes you want. Remember, though, there is a limit to your range. Pushing to far to fast can damage your throat to a point you'll never get there, so proceed with caution.

Do not POWER your high notes. If you have to scream to hit them, nobody is going to enjoy listening to you singing it. Keep your voice under control at all times, and not only will you sound better, you'll be able to sing much longer, without tiring out.

Also, remember to switch to your head voice, the higher you go. As the notes get higher, the sound wave the create gets shorter and closer together and do not need as much power to generate, so lighten up on the higher notes. Think of it as an upside down cone. Your power should be on the low notes and decrease as you sing higher.

Last word of advice. Listen to yourself sing. The only way to listen to yourself is to record yourself and play it back. When working on a phrase. Record/Listen identify what is working and not working, and fix it. Then record/listen again until it is right. Then proceed up your range.