I pair up two strips from the Jelly Roll and leaving them folded in half so I'm cutting through 4 layers, I cut - (2) 6.5 inch rectangles, (3) 2.5 inch squares. This gives me enough for 4 blocks two of each combination.
I think Jeanne made a pink/black/white version of this sometime last year (I looked for it to link to but it must have been on her old blog) . Her blocks were 9 inches finished if I remember correctly. These are 6 inches (6.5 with seam allowances).