First I cut a few 1.5" squares and then drew a diagonal line on the back of them.
The I sewed 1/4" either side of the diagonal line. Thank goodness for chain piecing. I always think this part is like sewing a kite's tail.
Then cutting and ironing. Voila ... half square triangles.
And I didn't get much further. Lucy the Cat looked on from the ironing pile.