Press and lay out the fabric so it’s nice and flat. If using several layers line them up so the selvedges are level.
I often find they are so quick and easy to do you can make several in one go by layering up the fabric and cutting 3 or 4 layers at a time.
Cut bias strips from the fat quarter the cutting width you need. Cut enough strips to sew together to make about 1m. In this case it was only 2 strips needed.