Starting with your organic forms with contour lines, there are a few things to call out here:

• It seems that you forgot to specifically aim for the characteristics of simple sausages as shown here in the instructions. Based on how you've approached your sausages here, it looks like you just weren't aware of this aspect of the exercise, rather than failing to achieve it - be sure to always go back over the instructions, especially when those exercises are assigned as part of your homework. For warmup purposes, you can go back over them every now and then, rather than each time.

• Right now, your contour lines are are roughly maintaining a consistent degree as we slide along the length of a given sausage. Instead, as explained back in Lesson 1's ellipses video, the contour lines will actually get wider as we slide along the sausage, moving away from the viewer (so they'll also get narrower as we move towards the viewer).

Continuing onto your insect constructions, you've got a bit of a mixed bag here, largely because you vary your approach between sometimes engaging with your drawing more strictly in three dimensions (thinking of it as though you're merging full, three dimensional forms together to gradually build up to a greater level of complexity), and working more in 2D on the flat space of the page, focusing more on capturing a pretty drawing rather than actually manipulating 3D forms. It's important to keep in mind that the drawings we do in this course are just exercises. Each one is a three dimensional spatial puzzle where we know what we want to work towards building, but have relatively simple pieces to combine together to get there. In having our brains solve that puzzle, we develop its understanding of how these things we draw exist in a 3D world, not as lines and shapes on a page.

You leveraged this well when working through the demos, where the considerable quantity of visual information from the reference images was already parsed and sorted out for you - there you copied over the individual forms and worked through the steps well, building up solid, three dimensional results. When tackling your own drawings however, you shifted your approach more to drawing what you saw, at least at first.

I'd say the tree hopper right at the very end kind of circled back to thinking somewhat more in 3D space (the initial masses of the head/thorax and the abdomen were considered more in three dimensions, but you were still not drawing complete forms as shown here - instead opting to just draw the things you saw in the 2D space of the photograph. The approach, as such, was still very different from what was shown in the demonstrations.

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. 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.

We can see this quite a bit in your drawings. It's present in this insect (red being where you cut into the silhouettes, blue being where you've taken an existing silhouette and extended it through the addition of flat shapes or individual strokes). These approaches are basically what we used in Lesson 3's leaves, but it worked okay there because we were already dealing with something that was flat, as explained here.

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.

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 on, 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, as a whole I really don't think you're that far off. I think you just got distracted by all of the visual complexity of your reference images, and ended up chasing it down a rabbit hole that took you off the intended path. As such, I'm going to assign some revisions below so you can take a step back and apply the steps from the demos to your own work.