How to construct a slash pocket

Step 6 Align pocket piece with pocket lining

Flip over the section you just stitched and understitched to face right side down. You will need to align the pocket piece to the back of the section, putting the pocket piece and pocket lining right side to right side (remember you flipped the pocket lining so wrong sides are facng in the previous step.)

This is where we actually make the pocket a pocket. Some people pin their pieces together once aligned. I don't really use pins unless there is some serious easing or gathering to be done.