A single watch is perfect for a vintage timepiece with a story to tell; the dial may be yellowed, but the second hand still ticks

A set of two can hold a pair of couple's watches: the men's watch is understated, the women's watch delicate, the hour and minute hands moving independently, occasionally meeting at the number twelve

A set of three is for a family of three; the children's straps should be shortened, while the parents' should be longer

An eight-watch set is enough to accommodate watches for each day of the week, plus a weekend watch

A set of 21 is a mini-collection: moon phase, diving, and aviation watches, each with its own time zone