Button suspenders add polish to a pair of classic trousers, or an extra edge to a pair of denim jeans. They're more durable than clip-on suspenders, because the buttons are sewn into place. Finding the right spot on the pants and sewing on the buttons is a relatively easy project that can be done in an hour or less.
Measure the holes on the suspenders, and choose buttons that are 1/8-inch smaller than that measurement. The button should match the pants fabric as closely as possible.
Pin the single suspender to the middle of the waistline in the back. Put the pants on and pull the suspenders over your shoulders. You'll be sewing on two buttons for each of the two front suspenders, and two buttons to anchor the suspenders in the back.
Adjust the two front suspenders to how you want to wear them. Pin into place. Make sure to space out the ends of the suspenders, where the buttonholes fall naturally and comfortably into place. You may have to fit the front and back a couple of times so the suspenders lay flat.
Remove pants and mark the six buttonhole areas inside with chalk.
Place a button near the chalk mark, about 1 inch away from the pant's edge. Double thread the needle, and starting from underneath, push it through the fabric and through the buttonhole.
Repeat this 7 to 8 times per button. Tie off the end of the thread with a double knot. Repeat this step for all six buttons.
There are also no-sew buttons that will hold suspenders in place. See the Resources section below for information.