Pinked Hems
Pinking shears, specialized scissors that cut in a zigzag pattern, are useful for quick hemming jobs on fabrics that don't ravel much, including most knits. After you've measured and marked your hemline, trim the edge using pinking shears. Then stitch a line close to the deepest part of the pinked notches all the way around. Pin the hem to the desired depth and either machine-stitch through all layers of fabric or, if you prefer an invisible hemline, slip-stitch by hand or use your sewing machine's blind hem stitch.
Machine-Turned Hems
The stitching on the machine-turned hems commonly seen in casual clothing is visible on the outside of garments. As such, it is partly a design element so your sewing pattern will always specify the hem's recommended depth. The basic technique involves turning the raw edge up by 1/4 inch, pinning it in place, pressing it flat with an iron and stitching all the way around. After that, pin the hem to the preferred depth, stitch through all layers close to your first line of stitching and press.
Hand-Rolled Hems
Only people very dedicated to sewing will have enough patience to master this time-consuming technique used to finish the edges of fine silk scarves, sheer fabrics and expensive handkerchiefs. Sew 1/4 inch all around the raw edge of your fabric and press with a cool iron. Weigh down one end of the fabric with something heavy, such as the base of your sewing machine, pull it taut and snip all the way around close to the stitching, a few inches at a time. Thread a fine needle and anchor it to the fabric's edge with a few tiny back stitches, then roll the fabric in your direction between thumb and forefinger until the machine stitching disappears. Hem all the way around the fabric using tiny and evenly-spaced slip-stitches.
Fabric Glue or Adhesive Tapes
No serious seamstress would be caught dead hemming garments with fabric glue or adhesive tape but many ordinary mortals, especially those who have never mastered the intricacies of needle and thread, appreciate the ease and convenience of these products. Temporary and permanent fabric adhesives are available, as well as iron-on tapes and those that form a bond without the need for heat. Some people even like to play it safe by using both on the same hem. Always follow the manufacturer's instructions to avoid damaging fabric.