Starting with your organic forms with contour curves, overall you're doing quite well here, but there's a couple things to keep in mind:

• The degree of your contour curves should be shifting, rather than maintaining the same width. The basic rule of thumb is that as we slide farther away along the length of the cylindrical form, the wider those cross-sectional slices will get. This is of course also impacted by the fact that these forms turn and bend in space, but farther = wider is a good place to start. You can refer to the Lesson 1 ellipses video though if all this seems to be coming out of left field.

• Be sure to draw through all of your ellipses two full times before lifting your pen.

Continuing onto your insect constructions, I can see that you've put a great deal of attention into considering how to go about building up from simple to complex, and there are many lengths to which you've gone to help your individual forms feel more three dimensional. This is something that is going well, although I have some advice to offer that should help you achieve this even more effectively.

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.

On this ladybug I've highlighted some cases of this - in red where you cut into the silhouettes of your forms, and in blue where you extended off them, adding partial/flat shapes but without defining how they're meant to relate to the existing structure in three dimensions.

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, I noticed that you clearly made a concerted effort to employ the sausage method in your constructions, and I'm very pleased to see it. There are some ways this can be improved however - most notably in simply being a bit more attentive to the specific characteristics of how those sausages are being drawn. Always try and strive for two ends of equal size, connected by a tube of consistent width. It's very easy to fall into the habit of drawing ellipses, or deviating from those characteristics in other ways, so it's important to be attentive to this.

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).

And that about covers it! Ultimately you're doing well, but keep working at applying the points I've raised here as you move into the next lesson. I'll go ahead and mark this one as complete.