Jumping in with your organic forms with contour curves, you're off to a great start. You're sticking very closely to the characteristics of simple sausages, with ends that are circular in shape and equal in size, and midsections that maintain the same width throughout its length. One thing to keep in mind though is that the degree of your contour lines should be getting naturally wider as we slide further away from the viewer along the length of the sausage - that seems to be something you're overlooking at the moment.

Continuing onto your insect constructions, there is a great deal you're doing quite well here, but I also have some advice that should help you get the most out of these exercises. A lot of it comes down to understanding the distinction between actions we take in two dimensions, versus actions we take in three dimensions.

There's a lot already present in your constructions that does an excellent job of focusing on 3D, with a lot of that coming down to the way in which individual forms are arranged in relation to one another. Rather than arranging them as shapes on a page, where they're all equidistant from the viewer, you're mindful of ensuring that the forms overlap in such a way that we understand some forms as being in front, and others being behind. That does a great deal to help make the overall structure feel more solid, although there is more we can do to make the individual pieces feel more concrete and tangible.

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.

So for example, if you look at this cicada, I've marked out some spots in red where you've cut into your silhouettes, and one in blue where you've extended off the existing forms. In all honesty, while you pretty frequently cut into the initial masses, the bigger concern is the tendency to put your initial construction down with fainter lines, then draw on top of it with darker ones. This leads to you redrawing everything, and in so doing, altering those silhouettes in small ways you may not intend.

Line weight in general should not be used as an opportunity to redraw or arbitrarily reinforce large swathes of your existing construction. Instead, focus its use on clarifying how different forms overlap one another, limiting it to the specific localized areas where those overlaps occur. Also, refrain from having line weight jump from one form to another - this can accidentally add partial shapes where those jumps happen, "bridging" across from one to the next, as we see here at the joint. This can have the kind of impact of taking your complex object, with its complex silhouette, and stuffing it into a sock, gently rounding out and simplifying elements of the silhouette, and flattening it out as a result.

Back on topic - 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 can see that you are making partial use of the sausage method (although you're not defining the joints between the sausage segments with contour lines, which is an important step, and not one you should neglect). 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.

And that about covers it! All in all, you are doing really well, but avoiding the issues I've called out here and sticking as much as you can to working strictly with actions taken in 3D space will make a big difference. You can of course continue to work on these points in the next lesson, where they all continue to be relevant. So, I'll go ahead and mark this lesson as complete.