This tutorial is how to hem a pair of pants. It’s easier than many might think.
1.) I always wash the pants first to allow for shrinkage
2.) Try on the pants with the shoe you’ll wear. Standing in front of a full-length mirror, fold the fabric up inside each leg so the bottom of the fold falls three-quarters of the way down your heel. Place a pin at the back of each leg; stand up and check the length in the mirror. Adjust as needed.
3.) Remove the original hem with a seam ripper.
4.) Take off the pants; turn them inside out. Starting at the pin on one leg, use a hem gauge, or ruler, to measure the length from the edge of the fabric to the bottom fold.
5.) Use that measurement to fold and pin the hem around the leg (use six pins).
6.) Repeat with other leg.
7.) Iron hems.
8.) With pants inside out, use gauge, or ruler, to measure 1.5″ of fabric from the ironed hemline. Mark with a marking pencil; repeat every inch, making a dashed line around the leg.
9.) Remove pins.
10.) Cut along the line with pinking shears to prevent fabric from unraveling; pin back in place.
11.) Repeat with other leg.
12.) Thread a needle with a single strand of thread, about three feet long; tie a knot at the end.
13.) With pants inside out, begin sewing a blind hem stitch at a side seam: Put the needle under the folded hem, pull through, then make zigzag stitches every 1.4″ . (As you go, pick up only one fiber from the pant, so the stitch is not visible from the outside.) Knot thread when done.
14.) Repeat on other leg.
15.) Iron finished hems.Source; Nicole Evangelista, tailor and costumer; TODAY and Saturday Night Live. Woman’s Day, January 2011; page 144