I learned about this technique last year. I attended a local quilt guild meeting where the speaker described it. She uses the slippery newspaper ads that come in Sunday's (or other) paper. Cut them into squares of any size and sew strips of any width to the paper on the diagonal and you have a very colorful scrappy block.
Step One: Cut some paper to size. I used five inch blocks.
Gather your strips. I prefer one inch strips but any size will do. Anything less than 3/4 of an inch is really to narrow, IMHO. Mix light and dark as well as some really bright ones
Press and sort
Prep your square. Smear some gluestick glue on the diagonal of your paper square and place your first strip, right side UP, on the glue. Press to set the glue. You can skip the pressing if you want and just put your next strip on top (right side down) and then press if you would like. Stitch. When I am using very narrow strips, I use the 1/8 in seam.
It is recommended that you set your stitch length to a small stitch and a #90 needle.