I'll try and keep my post short.
Sing how you want, but keep several things in mind. I think these 3 things can help you round out a well balanced voice.
Breathing
Projection
Vibrato
Breathing - This is very important. Proper breathing effects your tone, your phrasing, and vibrato. Practice taking deep breaths. Have you ever watched a baby sleep? See how their bellys go up and down when they breathe, practice breathing that way. Breathe so your belly is going up and down. When you practice singing with sheet music, put a slash above the words in the song where u take your breaths, and stick to it.
Projection - Practice singing with confidence. Imagine people are at the opposite end of the room, you want them to hear you. Never be nervous too, if you get nervous, you wont be able to project. Projection helps with high notes and vibrato.
Vibrato - I always throw vibrato in because it adds a touch of class to anything you sing. The person can have an OK voice, but if he/she has a killer vibrato, it'll make up for the "OK" voice. I've heard different versions of good vibrato's from different voice teachers. One teacher said 6 cycles a second is good, but I don't agree with her. 4 cycles a second is much better sounding in my opinion. It's your preference really though, when you start practicing vibrato alot, you'll be able to control the speed at which you vibrato. So you can go fast slow whatever. When practicing vibrato, practice in your normal register key. Then practice on high notes/low notes when you are comfortable with it in your regular key.
If you work on these 3 things while practicing, you'll be noticing your voice and abilities change quite quickly.