Don't waste money on a tailor when you can hem your jeans yourself.
Step 1: Determine length Put on the jeans with the shoes that you will usually wear with them. Cuff the pants to the desired length and then mark the length with chalk or a pin.
TIP: Have a friend assist you. They can cuff the pants, provide feedback on the length, and mark the desired length for you.
Step 2: Measure length of cuff Remove the jeans, measure the length of the cuff, and divide the measurement in half.
TIP: Ignore the original hem when doing your measurements. You are going to keep the original hem and hide the extra length inside the pant leg.
Step 3: Sew new cuff Pin the cuff at the new length and sew it in place. Sew as close to the original hem as possible. You now have a small fold of extra denim inside your jeans.
Step 4: Verify length Verify the new length by trying on the jeans in front of the mirror. If the length is off, mark a new length with chalk or pins so that you can make adjustments.
Step 5: Turn jeans inside out Turn the jeans inside out and press the extra flap of denim upward, toward the waistline.
Step 6: Tack fold Tack the extra fold in place by sewing a few stitches at each side seam.
TIP: If there is now too much fabric inside your pant leg for comfort, trim the extra material, cutting close to your new hem.
Step 7: Turn and press Turn the jeans right side out, put them on, and don't worry about tripping on the extra length.
FACT: Levi Strauss' original plan was to sell tents and wagon covers to people moving to California for the gold rush. Since there was no market for these, he instead manufactured durable pants for the miners.