Vocal warm up exercises

I have been learning vocal warm up excersises to ease my voice before singing, this is so that I am able to hit all the notes within a song. I used the vocal exersise were I will sing the words "Every time I get the opertunity to worm up my voice" I will do this but each time I sing the line we change the key so that it warms my vocal chords.

We also sung mini mini mini mini mouse and each time we sang this we would move up in key this warmed up my vocal chords and also widened my vocal range.