Things You'll Need
Socks provide the average homemaker with more than enough headaches. They go missing in the wash, there is always an odd sock that never meets its mate again, they get holes in them, and some are perfectly good except they have lost their elastic and won't stay up. Don't relegate those slouchy socks to the dustrag bin just yet. By hand-sewing four or five rows of elastic thread around the cuff of the sock, you can provide enough elastic to give new life to those socks and save money in the process.
Measure the sock cuff while it is laying flat on a work surface. Cut five pieces of elastic thread, each measuring 3/4 of the length of the flat measurement. Remember the elastic will stretch and provide the "tightness" necessary to keep up your sock. You don't want to make it too tight but just tight enough to stay up. If the wearer of the sock has very thin legs, you can use 1/2 of the length rather than 3/4.
Thread the needle with a piece of the elastic thread and tie a knot at the end just like you would regular sewing thread.
Hold the sock in one hand, with the cuff slipped over your fingers. Insert the threaded needle ¼-inch from the top of the sock cuff and sew in and out, in a running stitch. Make your stitches ½-inch apart. Sew around the cuff and make a stitch to lock the sewing. Cut the thread.
Re-thread the needle and tie the knot in your elastic thread and measure down one inch from the first row of elastic stitching. Move the needle down to that one-inch mark and repeat the running stitch around the cuff of the sock. When you reach the original sewing point, sew a stitch to secure your running stitch and cut the elastic thread.
Repeat for the other three pieces of elastic, moving the needle down one inch from each row of sewing until you've used all five pieces of elastic thread and have sewn five rows of elastic thread. Repeat for the other sock if needed.
Elastic thread can be purchased at discount, craft and fabric stores. There are also many online fabric stores that sell elastic thread in many different colors. Choose a color closest to the color of your sock when making “invisible” repairs. Mending socks with elastic thread is also a great way to close holes in heels and toes without the bunching up that regular sewing thread produces when sewing sock holes.