Pick one large blouse or shirt. Do up all the buttons. Turn it inside out and iron it flat. Pin between each button to keep layers together.
Measure up to just below the armholes and draw a line across with a Trickmarker (fading fabric pen) Pin along this line and along the bottom edge.
Draw a line at right angles to the line below the armholes on both sides creating a square or oblong. Pin and tack all around all four sides.
Remove all pins when you have finished tacking. Sew around all four sides. Trim fabric edge about 2 cms away from sewing line with pinking shears to prevent fraying. Cut diagonally across each corner to make corners easier to turn.
Undo buttons and turn to right side out. Add a cushion pad. Do up the buttons and your cushion is finished.
Reverse of cushion with buttons done up and two useful hidden pockets to hide things in. If you don't want the pockets simply remove them before making up your cushion. You can also make a cushion the same way using a cardigan with buttons down the front for a cosy winter cushion.