It's not my favorite kind of quilt sewing because, using the charm squares as a basis, you end up trimming every subunit to size so it's going slowly. You've probably done blocks from charm squares before. The small HSTs are made by drawing diagonal, horizontal and vertical lines on pairs of charm squares, sewing on either side of the diagonal lines, cutting them apart on all the lines and trimming them to 2" square. You get eight HSTs from a pair of charm squares. Then you make the hourglass blocks with two pairs of charm squares, 2 dark, 1 background and 1 light. You make two sets of HSTs, pair them up, sew on either side of a diagonal line and cut them apart. You get four hourglass blocks that can be trimmed to 3.5" square.
I have 24 blocks so far and need 41. Anyway, here are some of the blocks: