I was very lucky and had a professional quilter who also was a homemaking teacher. She was actually a substitute for the class! When we got ready to sew 1/4 inch seams, she handed out small index cards which the top line was actually 1/4 inch from the top of the card. She had us place our machine needle on that line making sure the card was stright! Then we took Blue painter's tape and put on our machines at the edge of the card! We put enough layers to make a sewing guide to push our seams up against. If the fabric wants to slip over the tape, then you haven't put on enough tape. We all sewed like pros from then on! She felt like the card was a more accurate method than trying to put the tape on the mark of the throat plate, and it was a lot easier!