To start, generally I wouldn't critique additional exercises that may have been included, but it looks like your leaves are coming along well, so I figured I'd just slip that in. Continuing onto your organic forms with contour curves, you're handling these quite well. You're sticking to the characteristics of simple sausages, and your contour lines are well controlled, fitting snugly within the forms.

Continuing onto the insect constructions, as a whole you're doing an awesome job - but fortunately for me (because otherwise I wouldn't have much else to say), there are some areas where I can offer some advice that should help you continue to get even more out of these exercises. That advice comes down to something we don't actually talk much about in the lesson proper, but I have plans to expand it in that direction, and it's good to know going into the animals material. It's about the difference between actions we take in 2D space - just putting lines down on a flat page - and 3D space, where we're actually defining solid, three dimensional structures and thinking about how they relate to one another within that three dimensional world.

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.

While you don't run into the issue of cutting into silhouettes super often, it does come up when you start your masses out with ellipses that are a little looser, as we can see in the areas marked out in red on this page. It's generally best to treat the outermost perimeter of the ellipse as the edge of the mass's silhouette, just so all of the stray lines are kept inside of its bounds. As for the lines I marked out in blue, these are areas where you've built off the silhouette of an existing form, but only in two dimensions - there's no clear way in which the space this encloses is meant to represent a specific form that exists in three dimensions - and where it has the potential of doing so, there's no clear way in which it actually relates to the other existing structures.

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.

Continuing on, one last thing I wanted to mention is that 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).

Anyway, as I said earlier on, overall you're doing an amazing job. While both points are important, and you should strive to apply them into the next lesson, you're doing very well, and I'm clearly seeing your grasp of 3D space developing quite nicely as you work through this material. I'll go ahead and mark this lesson as complete.