Starting with your organic forms with contour lines, you're largely doing a pretty good job, though your second page is markedly better in getting your contour lines to wrap more convincingly around the sausage forms (primarily because you're more willing there to overshoot those curves). I also noticed that while you are mostly doing a good job of sticking to simple sausage forms, you're falling short by a bit with some forms that get a little fatter through their midsection, or that have ends that are either of different sizes or not quite spherical. You are very close, so it's something you just need to keep in the forefront of your mind when doing this exercise as the simpler our sausage forms are, the more easily we can capture the illusion that they are solid and three dimensional.

Now, in many aspects you are doing an excellent job with your insect constructions. You're definitely thinking a lot about how to build things up from simpler forms, starting with your major masses and gradually introducing more simple elements to work towards a more complex object with more nuanced silhouette without losing the illusion of solidity. There are a few little hiccups in your approach, but by and large you're doing a good job.

One of the things that I noticed was that you aren't entirely consistent in how you construct your insects' legs. Sometimes you adhere to the sausage method, but there are several instances where you apply only certain aspects of it. It's normal that you'll come across plenty of insects with legs that don't appear to entirely match a "chain of sausages", but it's doubly important that you still apply the sausage method consistantly, adhering to all of its major points (using simple sausage forms, ensuring those sausage forms intersect and then reinforcing those intersections with contour lines right at the joint and no where else). This is because what we are creating with this is an underlying structure or armature that captures both the solidity and fluidity of those legs. Most approaches will either focus on one or the other - appearing very solid but somewhat stiff, or flowing gesturally but appearing flat. The sausage technique gives us the best of both worlds. From there, we can always build on top of it to add bulk where necessary, as shown here.

I definitely agree that you're also struggling with those cast shadows. The key to cast shadows is that they establish the relationship between the object and the ground itself, giving us something we can relate to easily (the floor) as a new way to understand the object. The issue with your approach is that you always kept the cast shadow the same distance away from the silhouette of the object at all times. Instead, the distance of the shadow from the silhouette tells us how far a particular part of the object is from the ground - so if it's all the same distance, then that tells us the object is really hugging the ground.

Instead, you'll have the part of the shadow cast by the foot cling quite closely to it (because the foot is very close to the floor), but as we get up into the leg, it'll start to move farther away. Farther still will be the body, giving us a sense of how the body is being held a distance above the ground. The shadow shape itself doesn't need to be exact, or even all that close to the object. It just needs to convey these distances in a way that will help ground the object. Here's how I'd approach the shadow on your hercules beetle.

As far as your proportions go, they're not that far off. There are some that stray a little, but you are right not to try and worry about too many things simultaneously. This course is focused on capturing the illusion of form and developing spatial reasoning skills - proportion will continue to develop with practice, as you get used to applying and developing your observational skills through many more studies. You're not struggling with it to such a degree that I'm concerned, so I wouldn't shift your focus there just yet.

So! With that, I'm fairly pleased with your results. I'll go ahead and mark this lesson as complete. Just remember that the sausage method is important not only in the context of insects, but in constructing any sort of gestural, flowing forms. We'll continue to use it throughout the next lesson as well.