Carol, love your quilt top, very serene.
Deb, I would suggest trimming as you go. I waited till the end and had a clump 7X6X1" of scraps that were just slivers but it took a long time and hurt my back to stand for too long. I did cut in sets of 20 and then went and did something else where I could sit but I really found myself regretting that I had waited till the end to do this part. Also, I had to remake a few tri rec units. If you're new to them, make sure your points at the top match and you will get a much more accurate unit. And read every line before you start, and again as you're completing each week, just to make sure you don't miss anything. Good Luck to you.