A euro hem is a convenient way to shorten jeans that are too long, since it uses the original hem of the jeans. This technique works best for jeans that have fairly straight leg openings, rather than flared jeans. You can hand-sew the euro hem or use a sewing machine. Many sewing machines have a toolbox on the front that you can remove so that the you can slip the leg of the jeans over the arm of the machine. This helps prevent you from accidentally sewing the leg of the jeans shut while sewing the hem.
Try on the jeans. To decide how much shorter you want the jeans to be, turn up the lower edges of the legs to make cuffs and adjust the cuffs as needed. Make sure the cuffed jeans are the right length when you’re standing up straight, not when you’re bending over.
Remove the jeans. Measure the cuffs, then adjust them so that the distance from the seam in the original hem to the bottom of the cuff is half the amount you want to shorten the jeans. For example, if you want the jeans 2 inches shorter, make the distance from the original hem to the bottom of the cuff 1 inch.
Pin the cuffs of the jeans in place. Make sure to measure the cuffs all the way around as you pin, so that they’re even.
Stitch around each cuff, just slightly below the stitching on the original hem. If the cuffs are very long, you may want to trim off the excess fabric and finish the raw edges with a zigzag stitch.
Turn the cuffs to the inside of the jeans, so that they won’t show. Iron the ends of the jeans flat to hold the new hems in place.