Starting with your organic forms with contour curves, there are a couple signs here that suggest you jumped right into doing the exercise and didn't reread the instructions:

• You didn't employ a central minor axis line to help align your contour lines

• You didn't stick to the characteristics of simple sausages

The contour lines themselves are for the most part quite well drawn - they're smooth and confident, while remaining accurate and snug within the silhouette of the form. You do need to be more mindful of how those contour lines shift in their degree as they slide away from the viewer, along the length of the sausage form. I can see you doing this in some cases, though not all. You'll find that the recently updated ellipses video for Lesson 1 explains why the degree should be shifting, in case you're not sure what I'm talking about here.

Continuing onto your insect constructions, I'm seeing a lot of examples that show you're developing a good grasp of how the marks you're drawing on the page represent solid, three dimensional forms - so the way you draw anything attaching to them after the fact tends to wrap around them in a believable manner. For example, I am very pleased with how you've approached the segmentation on this insect. Each addition reinforces the illusion that the rest of the structure is solid, and that is precisely what we're looking for.

There are however some approaches that I'd like to caution you away from. Because we're drawing on a flat piece of paper, we have a lot of freedom to make whatever marks we choose - it just so happens that the majority of those marks will contradict the illusion you're trying to create and remind the viewer that they're just looking at a series of lines on a flat piece of paper. In order to avoid this and stick only to the marks that reinforce the illusion we're creating, we can force ourselves to adhere to certain rules as we build up our constructions. Rules that respect the solidity of our construction.

For example - once you've put a form down on the page, do not attempt to alter its silhouette. For example, on this praying mantis' head you wrapped another rather complex shape around the head and down to the neck, effectively redefining the silhouette of forms that had already been constructed.

Its silhouette is just a shape on the page which represents the form we're drawing, but its connection to that form is entirely based on its current shape. If you change that shape, you won't alter the form it represents - you'll just break the connection, leaving yourself with a flat shape. We can see this most easily in this example of what happens when we cut back into the silhouette of a form.

Instead, whenever we want to build upon our construction or change something, we can do so by introducing new 3D forms to the structure, and by establishing how those forms either connect or relate to what's already present in our 3D scene. We can do this either by defining the intersection between them with contour lines (like in lesson 2's form intersections exercise), or by wrapping the silhouette of the new form around the existing structure as shown here.

You can see this in practice in this beetle horn demo, as well as in this ant head demo, but you've got plenty of good examples in your own work (specifically in how you wrap complete forms around existing structure to build up segmentation). This is all part of accepting that everything we draw is 3D, and therefore needs to be treated as such in order for the viewer to believe in that lie.

Continuing forward, I noticed that you seem to have employed a lot of different strategies for capturing the legs of your insects. It's not uncommon for students to be aware of the sausage method as introduced here, but to decide that the legs they're looking at don't actually seem to look like a chain of sausages, so they use some other strategy. The key to keep in mind here is that the sausage method is not about capturing the legs precisely as they are - it is about laying in a base structure or armature that captures both the solidity and the gestural flow of a limb in equal measure, where the majority of other techniques lean too far to one side, either looking solid and stiff or gestural but flat. Once in place, we can then build on top of this base structure with more additional forms as shown here, here, in this ant leg, and even here in the context of a dog's leg (because this technique is still to be used throughout the next lesson as well). Just make sure you start out with the sausages, precisely as the steps are laid out in that diagram - don't throw the technique out just because it doesn't immediately look like what you're trying to construct.

Now overall I am fairly pleased with the direction you're going, but I primarily would like to see you better employ the sausage method before I mark this lesson as complete. So, I'm going to assign a couple additional pages of revisions (and one more for the organic forms with contour curves exercise) for you to apply your understanding of what I've pointed out here.