I have several machines. I either have a 1/4" foot or use painter's tape and mark 1/4" and sew along that line. I like painter's tape because it is easy to see and doesn't leave any residue or harm the finish of the machine. I've also heard of using an old credit card and taping that at 1/4". I'm not sure how that would work however if your presser foot is wider than where the 1/4" mark would be.