First sew random strips together. You can join strips or add pieces of cut up blocks to make the length. Cut them into 4.5" squares.
Arrange the blocks into a four patch, with the stripes going in alternate directions. (I've mixed the patches up a bit, to get some variety.)
Cut two 4.5" squares from cream fabric, draw in (or iron) the diagonal. Put a pin on the bottom triangle, to mark the piece you will cut off. Sew along the marked line, and then again, about 0.5" away from the line on the pinned piece. Cut between the two sewing lines and press open. You will have two half square triangles. The bigger one is needed for the block, and the smaller one is a bonus! Cut four 2" triangles, mark the diagonal as before and place in the top corners of the two top blocks. Sew along the diagonal lines. Trim the outer corners. Open and press.
Sew the pieces together as a four patch. Hey presto!
And for every block, you get two free scrappy half square triangles! Now what shall I do with those?!