great way to use up scraps! i take muslin or any thin inexpensive fabric, decide on a size (usually about 14") pull out a strip of fabric (people who are avid string-quilters use any strip 1/2" or wider) place it across the foundation right side up from top left corner to bottom right. put your next strip right sides together over the first one and stitch down it 1/4" seam. flip open, press, add the next strip. you can go all in one direction to the corner then turn and go the other way or you can sew to each side alternating till the block is covered. after the foundation is covered take to cutting board and square up. I usually trim to 12 1/2" if i started with a 14" foundation square, but not everyone trims that much, trim what you need to make your blocks all the same size.
easy and fun! really uses up the scraps.