Use the arch PDF to mark the arches on your aprons. Mark on the inside of the aprons the position of where you want your turnbutton mortises to be, the turn buttons is what secures the table top to the frame and the mortises are how they are attached. These are only rough markings as you will be measuring these out once you have taken the frame apart. Paul uses a line to mark two of the turnbutton mortises on the two opposite aprons and one on the other two aprons.
Paul also marks out the shaping for the legs while the frame is constructed. He marks in 1” (25mm) from the outside edge on the foot of the table leg and 1” (25mm) from the apron at the top of the table leg. Use a straight edge to join these lines up to give a guide for the shaping, do this on each outside face of the legs.