Stand facing the furniture as if you are about to sit, and measure every cushion on its own: a seat and a back are two pieces. Write down width (left to right), depth (front to back) and thickness. If the old cushions fit well, measure them; if they are worn or missing, measure the frame. T-shaped seats need three extra numbers: the left and right outside edge to where each arm begins, and the back edge to the front of the arms. For odd shapes, send photos or a paper template.