The most that you need to work on is continuing to practice your ghosting method for more confident lines, and to also fully reach your lines from point to point as some strokes stop partly like in the rough perspective and organic perspective exercises, plus it looks like you went over your ellipses more than two times, so try and cut those down by ghosting more and letting muscle memory handle it. Other than that you show extremely solid execution and understanding on what the exercises ask, on top of an already blooming understanding of perspective shown by the rotated boxes exercise.