Things You'll Need
Chalk pencil or fabric marker
Heavy-duty sewing needle (size 16 or larger)
Iron and ironing board
Many people have a stack of folded, unworn jeans in the closet that they no longer wear because the styles no longer suit them. Instead of discarding your unworn jeans, you can have your jeans altered or alter them yourself. While taking your jeans to a tailor may be a simple solution, it can be expensive. With a sewing machine and basic sewing skills you can easily make some alterations yourself. This includes making jeans tighter around the ankle by taking them in at the seams. Doing so saves you money, and allows you to wear those jeans in the back of your closet.
Wash, dry and iron your jeans so they are clean and as flat and straight as possible. Turn your jeans inside out and iron them again.
Try your jeans on front of a full-length mirror while they are still inside out. Ideally, recruit a friend to help you with this step. Face the mirror and grab the inside seam at the calf of one of the legs of your jeans. Starting at the knee and working your way down to the ankle, place straight pins through both layers of fabric along the inside of the existing seam. Adjust and re-position the pins until you're happy with the new shape of the lower leg.
Remove the jeans very carefully while keeping the pins in place. Draw a line down the inner seam with the chalk pencil or fabric marker and a ruler, following the line of pins. Draw a line on the other leg that matches the first leg, checking the measurement and position with the ruler. Re-position the pins along the neatly drawn lines.
Insert a heavy-duty sewing needle in your sewing machine and thread the machine with thread that matches the existing thread of your jeans. Set the machine to a medium-long straight stitch. If possible, sew a test seam on a scrap of fabric that's a similar weight to your jeans' fabric and adjust the tension if necessary.
Sew carefully down the chalk line on both legs of your jeans. Back-stitch at the start and end of your seams, and remove the straight pins as you sew. Take extra care while sewing over the thicker layers at the hem. Trim the loose thread ends.
Tip: For a nicer finish at the hems, unpick the stitches and unfold the existing hems on each side of the inner seam. Continue sewing your new seam all the way to the bottom edge of the fabric. Re-fold and sew the hem to match the lines of the original hem.
Try on your jeans to ensure that the jeans fit at the calves and ankles the way you want them to. Make any adjustments and if necessary, unpick and re-sew the new seams. When the jeans fit as you want, cut off the excess fabric with your scissors so that only 1/2 inch of excess fabric remains.
Optionally, press the seams open with a hot iron. Set your machine to sew a wide zigzag stitch and sew along the raw edges of each side of the seam allowance. This will prevent the edges from fraying.