Draw a line, a wavy one with as many or few curves as you like. BUT do not intersect lines.
Lines can curve in on each other or be isolated islands around which other lines ripple.
Fill in the page with as many wavy, non-crossing pen strokes as you care to make. Think of the whorls of a fingerprint, eddies in a stream, knots and ridges in a plank of wood, psychedelic patterns of a concert poster. Once your drawing is complete, meditate upon it. Notice patterns and what is suggests. Here is my attempt at this exercise.