Your lines aren't meeting their end points. The first few exercises are fine, but in some of the planes exercises and the rough/organic perspective exercises, your lines are tapering off before they meet the corners. This indicates you could be lifting your hand too early, before you're actually done drawing the line, or possibly drawing the line too fast without an actual end point in mind. I'd say it's probably better to overshoot a line than undershoot it. No need to redo anything, just something to keep in mind for the future.

The ellipses look good and consistent, good job.