Sewing pockets closed will remove some of the bulk that can occur because of them on the upper thighs of pants and especially of jeans. It can also close the annoying gaping look that pockets often take on when you are in a seated position. The solution presented here is for jeans but it can of course be done on any sort of pants pockets.
Lay the pants/jeans out flat and pin the pockets closed (fig. 1 and 2).
Hand sew the pockets closed in small stitches (fig. 3).
Turn the garment inside out and pin the pocket fabric together. Cut away the bottom (now useless) section of the inner pocket leaving only a few cm so it can be passed through a sewing machine. Make sure that you do not cut into the jeans/pants fabric (fig. 4 and 5).
Use a small zig-zac stitch and sew the bottom of the pocket closed. This will also seal the raw edges. The edges should not be joined to the pants! (fig. 6)