Jumping right in with your organic forms with contour curves, you've done some excellent work here and have nailed all the major points I look for. You're sticking closely to the characteristics of simple sausages, your contour curves are drawn with confidence, care, and control, and you're including a nice shift in the degree, making the contour curves wider as they move farther away from the viewer. Very well done.

Continuing onto your insect constructions, admittedly these started a little weak - or more accurately, oversimplified - but definitely showed a good bit of improvement over the course of the set. That said, I do still have some important advice to offer that should help you continue to get more out of these exercises.

So in terms of the weaker start, that falls primarily to the first three constructions. Once you hit this one, there was a notable shift in the amount of information you were allowing yourself to pull from your reference image - so a noted improvement on the observational front - as well as a significant improvement in how you were arranging your forms, so as to create a more believable sense of depth. That is to say, in that construction (as well as the ones that follow) there's a stronger sense of one mass being in front, and another being behind, which on its own gives a greater sense of the overall structure being 3D.

That said, when it comes to the individual forms we're building up, there are certain actions we can take that occur in 2D space - where we're really just putting lines down on a page - and actions we can take in 3D space, where we're actually thinking about how the form we're adding exists in space, and actually respecting and reinforcing the 3D nature of the structure that is already in place, and which we choose will impact whether that existing structure continues to feel solid, or whether it gets flattened out.

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 some examples of this here, where you started with a large mass for the main body, but then ended up cutting across it, leaving the red area out. That is definitely something you'll want to avoid, because it is a manipulation of the shapes present on the page, rather than the 3D forms present in our imaginary 3D world.

Instead, whenever we want to build upon our construction or change something, we can do so by introducing new 3D forms to the structure - forms with their own fully self-enclosed silhouettes - 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.

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.

You can see this in practice in this beetle horn demo, as well as in this ant head demo. You can also see some good examples of this in the lobster and shrimp demos on the informal demos page. As I've been pushing this concept more recently, it hasn't been fully integrated into the lesson material yet (it will be when the overhaul reaches Lesson 4). Until then, those submitting for official critiques basically get a preview of what is to come.

Now, I did notice that you were making a lot of use of the sausage method when constructing your legs - or more accurately, you were making partial use of it. You stuck well to the characteristics of simple sausages as before in most cases (although there were a few minor places where you'd veer more into the territory of stretched ellipses, like here on this ant's leg. but generally that was fine. What was more frequently missing was the contour lines that define the joint between the different sausage segments. Furthermore, I can see that you pretty much stuck to representing the entirety of the leg as a basic sausage chain, without any further development of the structure in most cases.

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, without leaving anything out.

Now, as you did improve quite a bit over the set, and as both of these overarching concerns can continue to be addressed into the next lesson, I am going to go ahead and mark this one as complete. Just be sure to keep pushing yourself to observe your references more closely, and while it's great to ensure that your first steps keep things nice and simple, don't be afraid to continue building up those structures, one little bit at a time. It can definitely be daunting - and more importantly, time consuming - but working one step at a time is how all great things are made.