Arrows

Pretty good, try not to repeat lines, and exaggerate more how the arrows get bigger as they get closer to the viewer. Don't forget you can use lineweight to clarify overlaps as well.

Organic forms

Pretty good overall too, only thing is that you got some of your contours a bit wobbly, remember that confidence is always more important than accuracy, so try to be careful with that.

Textures

Good job overall, don't use hatching. Only use cast shadows, nothing else. Neither gradiations on black. You should only use the same tone of black, no values, no hatching, only areas of black. Dissections look pretty nice too, though you are focusing a bit too much at contours at times, remember that you should here too only draw cast shadows.

Form intersections

Good job overall here as well. Don't forget not to repeat lines, you've done it a few times. And remember that the objective of this exercise is to mantain consistent foreshortening, and to do that it's easier to do it with shallow foreshortening boxes, so focus on them on next attempts.

Organic intersections

Feels pretty 3d, but the linework is a bit scratchy. Here as well don't forget that confident lines will always be better than accurate lines, so don't hesitate on sacrificing accuracy to get your lines more confident.