This exercise is to raise power, and should always begin with a focusing breathing exercise.
Now let your breath become sound…any sound you like…a moan…a sigh…a giggle…a low hum…a howl…a melody…chant the wordless sounds of the vowels…
Let the power build, and let the power guide you. Never try to force it. Let it grow gradually. The chant may peak suddenly, and drop to silence, or it may rise and fall in several tides of power. Let it direct itself.
When everything is silent once more, take a moment of silence for relaxation. Before you, or the group gets restless, ground using this exercise.
Exercise courtesy of The Spiral Dance by Starhawk