If overpacking is a familiar part of your travel routine, the 5-4-3-2-1 packing formula is worth trying. It offers a simple way to put together a compact travel wardrobe without leaving you with too few options. So, what exactly is the 5-4-3-2-1 packing formula? The formula breaks your travel wardrobe into five categories: 5 tops, 4 bottoms, 3 layers, 2 pairs of shoes and 1 special item. A beach holiday will need a very different wardrobe from a winter trip to the mountains.