[header] How to warm up your singing voice [title] Open up your throat. [step] One of the first and easiest steps to warm up your body and your throat before you sing is to open your throat and diaphragm by yawning. Gently force yourself to yawn by opening your mouth as though you were about to yawn. 
As you do this, think about yawning, or watch a video of someone yawning to initiate your own yawn. [substeps] Repeat this two or three times to fully open your throat and diaphragm.