Ok. Spoiler: Lorge picture Bought a remnant of some nice lining material, cut a square six inches deep and twice the width + 1 inch the existing pocket, French seams on two sides. Cut out the bottom of the old pocket, French seamed the new pocket to the old pocket, and felled the flappy bit down so it isn’t bulky in my skinny jeans. It was a fairly difficult project, honestly. I was dealing with narrow seam allowances, weird angles, and bulky jeans that got in the way constantly. I did about half of it by hand. New pocket is about 9 inches deep, plenty deep enough for my phone, headphones, and charger. I don’t use my left front pocket for anything, so I left it small. I have enough lining fabric to do this to at least a couple more pairs of jeans.