I would add a 6 x 24 ruler as well. And check to see if you can easily see the lines when laid on fabric. I personally like rulers with black lines vs. the yellow ones. Far easier to read. Lay the ruler on top of fabrics that you're attracted to and see what works best for you. The rotating mat really is the cat's meow! Especially for trimming up squares. I've just done almost 300 2 1/2 in. HST's in the last couple of days. And get some extra blades for your rotary cutter as well. Nothing cuts better than a new blade. But you want a mat at least 24" in one direction for cutting larger pieces of fabric.