Match the subject to the space you have
Placement dictates composition more than most people expect. Forearms and calves are long and curved, so vertical subjects work — snakes, swords, botanical stems, panels of script. Chest and upper back give you width, which suits wings, animals with spread postures, and symmetrical pieces built around the sternum or spine. Shoulders and outer biceps are rounded, so anything with a strong straight edge will fight the curve; circular and spiral compositions sit better there. Ribs and thighs give you the largest uninterrupted canvas on most bodies, which is where dense narrative pieces live. Before you fall for a design, hold your hand over the spot and picture the shape it needs to be.
