Many vocal experts insist that one of the best preparations for singing is also the easiest: drinking plenty of water. Properly hydrating before and during warm-ups promotes a more relaxed, lubricated vocal tract and allows your vocal cords to be gently stretched with less risk of injury or discomfort.
One standard vocal exercise is the descending scale, in which you start at the top of an eight-note scale and sing down (i.e. do, ti, la, so, fa, mi, re, do) using the syllable "noo." With each repeat, move up one half-step with regard to key. Try changing this exercise up by substituting "nee," "nah," or other similar syllables. You may also which out the consonant "n" with "m" in any of these syllables.
Begin this warm-up by inhaling while holding the mouth as if yawning. As you inhale, feel the air on the back of the throat. Then put the lips together gently and buzz, making a sound like a motorboat, as you exhale. Vocalize as you trill your lips, beginning with a pitch that is comfortable for you. Experiment as you repeat the exercise, gently lifting the pitch up or down as you exhale. One variation of this is known as the "octave slide," and involves starting on a note while trilling, then sweeping up one octave, and back down again.
Exhale by producing a steady "hmmmmmmmm" which is comfortably in your vocal range. Halfway through the exhalation, change the "hmmmm" to an "ahhhh," changing nothing but the opening of your mouth. You should feel a consistent level of vibration in your face with both sounds. You can also try moving from a low pitch to a higher pitch, or vice versa, while making these sounds.
Many singers practice repeating challenging phrases to create better flexibility in their articulation. The goal is to say or sing the phrases without producing excess muscle tension in the tongue, jaw or lips in order to articulate clearly, as these tensions compromise vocal ease. Tried and true favorites include "Peter Piper picked a peck of pickled peppers," "Tip of the teeth, the lips, the tongue", and "Sally sells seashells by the seashore." However, any phrase which requires tricky articulation will work.