Spent some time patching jeans for my grandson who has a penchant for shredding the right knee in all of his pants. Thought I would share how I did it and show photos of the finished pants.
I first opened the flat seam on each pair of pants just enough to be able to lay the area to be patched open flat. Then I trimmed away excess fuzzies and strings around each hole, cut a soft scrap of denim just large enough to cover the torn area with about 1/2 inch all around the outside (some of these were very strange shapes). I changed to a jean needle (size 16) and sewed the soft denim scrap with a zig-zag stitch to the inside of the pant leg just to stabilize the area and to make sure it would feel comfortable. Because some of the pants were stretched around the torn area, I had to work to make it lay nice and flat.
Then I measured and cut a larger square or rectangular piece of sturdy denim to use on the outside (depending on the size of the hole, you could cut other shapes such as hexagons, ovals, stars, etc.). I made them fit between the seams of the pant leg so that I would not have to sew over the heavy seams. I actually made two for each pair of pants so that both legs would look the same, although only one leg on each pair actually needed patching.
Finally, I tacked down each patch just using a simple straight stitch and then went around again with a variety of decorative applique stitches that are one my machine. Finally, I finished each patch with decorative stitching that added some design elements that also made each patch sturdier. Finally, I resewed up all the seams.
For three pair that had frayed cuffs, I cut off the old cuffs and added new ones. My grandson thought the pants really looked cool and has been wearing them everyday since I finished them. He is still young enough to think Grammy is wonderful!
I thought they turned out pretty cute (as did my husband). Photos are below: