The flared jeans fashion has roots in the bell-bottoms of the 1960s and 1970s. According to the history blog Aurora History Boutique, the flared trousers of U.S. Navy enlisted uniforms inspired the bell-bottomed jeans worn by hippies decades ago. The flared jean made a fashion comeback in the 1990s, and may come back into fashion. Here' how you can jump ahead of the fashion trend.
Use the seam ripper to rip the outside leg seam from the ankle hem up to the knee. Measure the exact length of your ripping so that it can be duplicated on the other leg.
Decide how large you want the flare to be, and cut a triangle from your chosen fabric accordingly. Mark and cut the shape of a triangle from the fabric, where two sides measure the length of the ripped seam plus one inch, and the third side is the width you want to increase the flare of the jeans plus one inch. The wider the base of the triangle, the larger the bell on the trousers will be.
Pin the fabric triangle into the ripped seam so that it overlaps the denim on the inside of the leg by one half inch on both sides and extends one half inch below the hem.
Stitch the fabric in place on the sewing machine, making sure to stitch over the top point of the triangle at the knee several times for reinforcement. Fold the extra half inch at the hem back toward the inside of the leg and stitch it in place so that the hem of the jeans is even with the hem you create on the added fabric.
Repeat the whole process on the other leg of the jeans, using the exact same measurements. Trim any stray threads, and try the flared jeans on.
Be creative with the fabric you choose for your insert. Consider patterns and bright colours for a bold fashion statement.