organic forms

in both ellipses and contour lines, the ellipse and the lines are uniform. you did not cleary use the perspective.

texture analysis

your texture did not transition well. it is ok but please correct it in the 25 texture challenge.

Arrows

In general they are rather clean but I would recommend trying varying the width more and try some new shapes to get a better understanding.

Sausages

Always draw through your ellipses twice. https://drawabox.com/lesson/1/11/drawingthrough

Some of your contour lines are pretty shallow, most notably the ones in the bottom left https://drawabox.com/lesson/2/5/shallow

There are also mistakes of curves not being parallel to sausage's main line. Here is my tip on how to think about curves: imagine that these curves are fragments of ellipses. Therefore if you make your curve as an ellipse (in your mind) it should make sense.

Textures

The transitions are not so smooth because it's easy to notice the black bar. Other than that it seems to be pretty fine because this exercise is rather hard.

Dissections

• There are a lot of missed opportunities of breaking the silhouette.

• Textures are rather simple, it seems like you haven't spent enough time at looking at your reference and simplified it in rush.

Intersections

Boxes are wobbly and there are almost no actual intersections. Spheres also have to be drawn twice because they are ellipses.

You shouldn't hatch curved surfaces.

Organic intersections

I would say they are good, though it would be nice to add some lineweight to intersecting lines to make the drawing more legible.