He returns to the altar and replaces the wand. Other methods can be used. However many covens also use the dance, the cords, the great rite - actual or symbolic, and other methods. Always remember there is NO one right path. There is also no one right way of casting a circle.
Different traditions differ greatly.
Part of the circle closing was also adapted from Starhawk. Many people like to elaborate on the invocations at the quarters and present them in poetic formats, as they do with the invocation of the Lord and Lady.