In the rough perspective boxes, it looks like every now and then there was a bit of misalignment with the drawn-though side of your boxes. It's the thing I have trouble with and I'm sure it will be everyone's worst enemy. I did however get better at them by acknowledging that they were tough for me, then taking extra time to visualize them in my head and ghosted them more. I think you would improve greatly by just taking an extra second to think about where they might go once the box is finished. You got this and good luck!