Looking to improve

These are starting to feel like good brainstorm sketches, rather than laboured full detail renders, which is a good thing. Your line weights are starting to show some control as well, which is helping define the sketch.

I think that it is important to present the sketch properly as well, so while it may seem minor, to push you along further perhaps consider some minor cropping (if needed) of your scans to give the page a more refined composition.