I really do not like the word contouring, because it implies changing the shape of a feature. I do, however, like one specific contouring technique that gives strength to the eye and definition for women with puffy eyes or receding lids.
Use your medium shadow (or one shade darker) with a contour brush. The idea is to apply a sideways V shape at the outside third of your eye; it will frame your eye nicely.
It involves two strokes: The top stroke should start at the upper outside corner of eye and work the shadow inward, down toward eye crease. The second stroke should start at outside lower corner of eye at the lash line work shadow inward and up to crease, meeting the other line. Pat the shadow with finger to soften edges.
To contour for day, use this same technique, but choose a soft color that doesn’t need blending. Try a deeper color for night or for a special event.