To darn holes in jeans, you will need:
Sheers (or sharp scissors)
Denim spool of thread
Iron denim patch on
Turn the jeans inside out, exposing the hole. Lay the pair of jeans on a hard, flat surface (such as a table or an ironing board) with the hole facing up.
Use a patch of denim matching the color of the torn jeans that is large enough to cover the hole. Denim patches can be purchase at most craft stores. If you must, you can cut fabric from the jeans pocket (the one that doesn't get a lot of use) or use a piece of denim from another pair of denim jeans if you have no other options.
Cut out the denim patch a bit larger than the hole, in any shape you prefer. Lay the patch over the hole and pin it into place, around its edges and through the patch underneath the jeans.
Use a sewing machine to darn the hole. Set the sewing machine on a fine setting. It’s foot should be on an embroidery setting. Place the sewing machine on a zig-zag setting, guiding the patches’ edges along the sewing machine’s stitch. You want to make sure that the hole’s edges are completely stitched up. For holes that are round in nature, make sure that you sew all the way around the patch. If the hole is rectangular or square, only sew a few corners of the hole and pivot.
If you do not have a sewing machine, darn holes in jeans with denim iron-on patch. These iron-on patches can be purchased from a craft or fabric store. Simply follow instructions as directed on product label. Generally, these patches can darn a hole in jeans just by ironing the patch over the pair. However, these patches can weaken overtime and rip from constant washing and drying. To secure the patch, stitch denim thread onto the edge of the patch with a needle, pulling the needle up and through the jeans, making at least five to ten stitches per inch.