PIN pocket to sling tail. BASTE pocket around on all 4 sides. Be careful with the zipper. Don’t break your needle.
NOTE #1: This would be a good point to test and see if your pocket size and placement is good. Can you still adjust your sling well? Does the sling fit inside the pocket?
Note #2: Also, I added a little fabric loop in the upper left corner between the pocket and the sling. So that when flipped inside out, I had a nice loop to hang/carry my sling pouch by.