Practice. That's the main thing that'll make you improve your singing skills. Sing songs by your favorite bands, or sing ones you've wrote yourself. Be sure you take breaks in between your singing practices *don't sing for hours and hours straight without resting*. Your vocal cords will need rest and if you keep going and going without giving them time to rest, you could end up causing damge to them. Be sure to get drinks *mainly water*, to keep yourself from getting dehydrated and to help keep your throat from getting sore.
And these are your 3, main warm ups that will REALLY help you out.
1) Breathing – Vocal Warm-up Exercise
Breathing affects the tone. Therefore, you have to breathe deeply by utilizing your diaphragm. The tone of your voice will be fuller and even smoother if you breathe deeply. Practically in this kind of vocal warms-up exercise, you have to put your finger up to your mouth and say, “shhh”. Make sure your breath is gone then just relax and allows the breathe come in automatically. Do this exercise for 5 times as a set.
Another breathing vocal warm-up exercise is slow breathing exercise. Do this by start inhaling slowly and mentally count to until 20 seconds, then exhale slowly until you have again reached 20 seconds. You will be able to control your breathing naturally if you do this about 5 times in every set vocal exercise.
2) “Lip Rolls” – Vocal Warm-up Exercise
Some call it the “motor boat” exercise. In this exercise, you have to put your lips together then exhale to make your lips to sort of flap. The lip rolls pretty much loosen up your vocal chords and they also train your vocal chords after several months of consistent practicing. It’s is to train you to control the flow of air without straining your vocal chord and voice at all. Some how, it’s related to the octave as well. Therefore, for a better result, you can begin this kind of vocal warm-up exercise with a low note first, and then work it up to the higher notes. You can work it back to low from high once you have reach the high one from low.
3) Multiple Vocal Warm-up Exercises
That’s the multiple work outs which provoke more flexible exercise styles. You can start this multiple vocal warm-up exercise with “mum and do nay, yay”.
Next, you have to do a couple of two syllable words to the same scale. “la ga” and “yah”, “ga” is the examples of the two syllable words. You need to open your mouth and relax the jaw when you’re practicing it. And make sure your jaw doesn’t move.
Other tips/info that's sure to help you - You have to discipline yourself to practicing these vocal strength exercises consistently in order to see the obvious results. I’m sure you will be shocked with he improvement after few months of your hard working exercises. You will realize that your tone will have strengthened and you vocal is voice become clearer, maybe even stronger vocally after few months of these vocal warm-up exercises.
I hope this help you out, if you need anything else, feel free to let me know.