If ready- made piping is not available or if you just want to make your own, the piping foot is ideal for the job. The piping foot is designed with two grooves on the underside and will hold and cover the cord when making piping tape. It can also be used for attaching piping. Maximum cord size is 5 mm.
Place the piping between two pieces of fabric and the piping will be sewn into the seam itself. Cut the piping so it's a bit longer than the seam you want to sew it to. Like, really close, which is where the piping foot comes in handy because the foot doesn't get in the way of the needle.