I dont think I saw this suggestion already... some of my blocks have half square triangles, which can be tricky if you have to make them sooooo small [3/8"!!]. The way I have found easiest for me is to use the smallest [1/2" finished size]thangle and make all you need at once. after you take off the paper and press them, then carefully cut down to the right size [remember your 1/4" seams!!!] you only need to match the diagonal seam with the diagonal 45 degree marking on your small square ruler and trim two adjoining sides. example - if your block has 4 half square triangles - one in each corner, you need two paper square thangle units for each block - 24 for 12 of them :)