Transfer markings of where the pocket placement will be to the main fabric piece.
Cut the pocket and lining the exact same size and shape
Pin right sides together
Sew starting off center from the bottom, up around one side, across the top, down the other side and stop off center on the other side of center, leaving a gap for turning later.
Clip corners and trim seam allowance
Turn to correct side through bottom opening
Press, making sure to turn the bottom gap under along the stitch line
Place pocket on main piece, pin in place
Top stitch pocket in place and backstitch at both corners