Laying a stair runner is similar to laying carpets in general, you just need tackless strips to hold the carpet firmly to the steps and to prevent slipping while walking up and down the stairs. The runner should always run downward. Keep in mind that depending on the direction and size of your stairs, instructions could vary. You can choose a runner that is a different colour from your stairway, and even mix it up with patterns and different types of padding or carpet if desired (such as beach mat or hemp).
Use a small hacksaw to cut the tackless strips to fit the stair width (you will need two strips for each step). Hammer one to the horizontal part of the step and then to the base of each rise on the vertical part of the step. Make sure that you allow a gap of 3/4 inch between the strip on the riser and the first tread strip in order to create space for the carpet to be pushed into the corners.
Cut single pieces of padding to fit over each tread and the riser below so they nudge up against the tackless strips. Make sure they do not lay over the strips. After they are in position, staple or tack them in place. Cover the entire staircase this way.
Cut the carpet to fit the width of the stairs, then start to fit the carpet from the top toward the bottom. Use the flooring chisel and press the carpet's top edge onto the tackless strip at the back of the tread at the stair top. Work down over each tread and rise, using the chisel to push the carpet back at each angle.
Fit tackless strips and padding to the landing. Overlap the end of the carpet over the top step and down the riser below.
Work from the bottom to top and do not attach tackless strips to the risers of each step.
Fold the carpet to fit flat against each step. For excess carpet in corners, trim the sides underneath and fold.
Hold each section in place with 1 3/8-inch long tacks and secure each part of the runner tightly.
Always be careful when working with sharp instruments, tacks or needles.