I don't turn my straps rso anymore. I have done the 'string' method and even have a tube turner. I cut the strap 4 times the finished width. Press in half, wrong sides together. Fold each side to center (press line) and press ends in. Stitch the three sides and you're done. If you don't have enough fabric to do the above, you can just press all raw edges in 1/4", and then press in half and sew. I have made a lot of aprons and I like the body of the ties when they are 4 layers.