Just as when you are warming up your muscles prior to doing your workout, you have to warm up your vocals before you rehearse. Relaxing and stretching your vocals ensures healthier voice and when it is put in good routine, it will help in increasing your vocal abilities and range.
https://www.youtube.com/watch?v=fSqMVGw4XR8
Ways to Warm Up Your Vocals
Luckily, there are numerous ways on how you could warm up your vocals and some are discussed in the next lines.
Number 1. The Straw Technique
Humming or exhaling a tune through a straw is a wonderful breathing exercise. When breathing is concentrated using the straw, you’re focused primarily on breath support.
You may do this when humming a song you’re practicing on the straw. Inhale through the straw or you may inhale outside of it if you’re feeling lightheaded.
Number 2. Humming
Among the gentlest and simplest ways of warming up your voice is doing it with a hum. It is recommended with major pentascales and work your way up half steps.
Number 3. Lip Trills
Take a breath and then, send it between your lips and let it vibrate. Be sure that your lips are relaxed and you’ll find yourself doing lip trill.