Step 3: Mark, Cut, Iron, Fold, Sew Inner Hole
1) Lay out the shorts and you'll (hopefully) be able to see the pocket through the hole (Pic 1)
2) Trace the hole shape to the pocket (Pic 2).
3) Cut 10mm inside the line (Pic 3).
4) Fold, Iron, and Sew down the flap at the crease (Pic 4)