Warming up your voice is something that can be done as you are getting ready for the day and as quick as 10 minutes. Below are some ways to warm up your voice.
These are great warm ups to do in the morning. Remember to always start by warming DOWN not up
Introduction - 2:46 "Body Warmup"
By learning to wake up the proper torso muscles, neck/throat tension can be greatly reduced. Learn more about the benefits in this section.
Coordination & Conditioning - 4:13 "Releasing/Awakening The Power Muscles"
Coordination and Conditioning are one and the same for this lesson. Simply follow along with me, performing each action as I explain it.
My suggestions:
1) Do this (Yes, all 4 parts) EVERY day. Don't be fooled by the simplicity of some of the exercises; each one is IMPORTANT :D
2) For your first week, watch both the Coordination and Conditioning sections of each video, to ensure proper form. You'll get much more benefit from 5 minutes of quality practice than you would from 30 minutes of unfocused practice.
Source: Eric Arceneaux