You can do this by laying out all the pockets side by side and remembering to allow 15mm all around for a seam allowance. Like so:
11. Now you can start attaching the pockets. Place them where they are meant to go and sew around using a smallish stitch. Don’t worry about the raw edges, they will fray nicely in time.
Work from one side to the other starting with Pocket C. Pocket B can be a little fiddly, just pin the center front of the pocket where it is mean to go and squash the 'box' corners as you go around them - remember that this is a pocket with depth so sew the edges to allow the pocket to 'belly' open. Don’t try to sew it completely flat like the other two pockets.
12. Finally pin the two large pieces together face to face and sew all the way around. Don’t forget to leave the zip open so you can turn it the right way round!!