Sometimes if you cut the largest piece first you will wind up with two pieces from which you need to cut the remainder, but neither piece is large enough, or you will be wasting fabric that you may need later. It can be really important to map out what you are going to do. First, measure your FQ. If it's not square, figure out how big it would be after you squared it up. Then draw the FQ, using its actual dimensions, on a piece of paper or in EQ and draw in the pieces that you need to cut. You may need to do that more than once, in case the first plan doesn't work. I drew yours in EQ, showing the cuts I would make, very similar to what ManiacQuilter2 suggested.