Arrows look good, hatching looks a bit rushed though, and remember that additional lineweight should be added with confident ghosted drawn with shoulder lines..

To improve their sense of 3d, you can exaggerate more how they get bigger as they come towards the viewer, both by making the space between folds bigger and the arrow itself bigger as well.

Organic forms are looking pretty good, though some of them are pinching a bit and have a few pointy ends. Remember they should be 2 identical balls connected by a tube of consistent width.

Ellipses are a bit wobbly at times, so remember that always confidence is more important than accuracy, ellipses are shifting nicely so good job!

Textures look pretty good, and same goes for dissections the textures wrap around the forms nicely, you are making a good use of the silhouette, and I can see you are focusing on the cast shadows when drawing thme.

Form intersections look good overall, though I can see you are adding a lot of lineweight. To keep it more clear, only add lineweight to overlaps, and remember to add the lineweight with drawn with the shoulder, ghosted, confident strokes. You also have some boxes that get more extreme perspective. The main purpose of this exercise is to mantain a consistent foreshorttening in all of their forms, so they resemble they share a common space. To do that easier, you can aim for all the forms to have a consistent shallow foreshortening, as it's easier to manage.

Ellipses are getting more confident in this exercise, so I can already see improvement from the previous ones!

Organic intersections look pretty solid, but they have a few issues, first one is that you aren't drawing through all your forms. Remember to draw every sausage completely, it doesn't matter if it gets covered by others. Try to push your shadows more as they are a bit too small. Sausages are looking a little bit stiff to so try to make your lines more confident.