Iron the interfacing onto the front trouser.
Notch the curve and reduce bulk.
Turn the pieces around so the wrong sides are together and press.
Attach the back piece of the front hip pocket using a 1.5cm seam allowance. Reduce to 1cm.
Secure everything together using 2 short lines of stitch, one at each end of the pocket.
Take the back trouser piece and attach it to the front trouser using 1.5cm seam allowance. Overlock the edge.
Press the seam line.