After making sure the cutting and piecing is correct I then cut the required number of pieces and then sew together.
I find that when I cut a few and piece then I have to refigure the total number I will need for the blocks.
Also I will know if I have enough fabric. I got into this twice recently when I did a few and then cut some more. It took me more time to keep track of number cut and number needed. It was frustrating so now I cut all I need and then start sewing. Helps me to keep it organized. Everything goes into zip lock bags.
I sometime sort individual blocks into paper plates and write any reminders, number etc directly on the plate. This also helps keep things organized.