Measure the diameter of your nailheads. Divide the diameter in half, and then add one-eighth of an inch.
Turn the ottoman on its side. Measure up from the bottom of your ottoman by the amount from Step 1. Mark the spot with tailor’s chalk. Hold a straightedge at the chalk mark, and draw a chalk line parallel with the ottoman’s bottom. Repeat with the other three sides.
Add one-sixteenth of an inch to the nail head diameter from Step 1. Measure along the chalk line on each side of the ottoman, and chalk cross hatches on the line at intervals equaling your result.
Press a bradawl into the chalk-line crosshatches, piercing the fabric or leather. Twist the bradawl gently into the wood once you’ve pierced the fabric or leather.
Insert the posts of the nailheads into the bradawl holes. Hammer the nails into the ottoman until the heads rest against the fabric or leather. Use a nylon- or rubber-tipped upholstery hammer to avoid scratching or denting the nails.