1. This is actually a fairly new addition to Lesson 0, but right at the end of this video about the tools we use I explain how you should be sitting at your desk, in terms of the height of your chair and desk. That said, no - the fact that your hand blocks your strokes isn't an issue, because you're not meant to be steering your strokes with your eyes anyway. Not something to worry about, as the ghosting method has you invest time into the planning/preparation, which makes certain sections not being visible upon execution a non-issue.

2. Applying the leaf technique isn't a bad thought - although one thing that gets in the way is the fact that wings are not flat, and so we don't have as much freedom to simply modify their silhouette, in the way we can with leaves and petals. Instead, we build up the wing structure as something more three dimensional, then attach feathers to it more similarly to how we handle texture - because that is essentially what they are. This diagram may help.

3. You don't - not directly. At least, that's not how this course is intended to be used. Rather, these are all just exercises which train your spatial reasoning skills, helping to develop the way in which your brain understands the things you're drawing as they exist in 3D space, rather than just lines on a flat page. Ultimately when you draw your own stuff, you're welcome to do so in whatever way you feel comfortable (or in whatever way whatever courses you're taking instruct). The difference is that your brain will, as that spatial reasoning skill is developed, do a better job of maintaining the understanding of how those 3D forms all relate to one another. In effect, each construction is a 3D spatial puzzle - our reference defines the direction in which we want to work, and we gradually work our way there, building up 3D forms upon each other, and defining the relationships between them in 3D space. All of this rewires the way in which our brains perceive the things we draw. I actually talk about this across a couple of the new Lesson 0 videos - I'd recommend that you check out all the new Lesson 0 video content, just to get yourself a refresher/update on what this course is really attempting to do for you, so you better understand how the work relates to that goal.

Anyway! Starting with your organic intersections, these are looking solid. You're capturing a good sense of gravity in how they slump and sag over one another, and they all feel quite solid. Your cast shadows are also demonstrating a good sense of how the're being cast on surfaces that are rounded, and turning away from the form casting them, and maintain the implication of a singular, consistent light source.

Continuing onto your animal constructions, your work here is mixed, and I think it comes down to the fact that your use of construction is generally decent - there are definitely things we can do to push it further along, but you're headed in the right direction there - but your observation is severely lacking, resulting in you working a lot more from memory than you ought to be, rather than looking at your reference frequently in order to inform the choices you make with each new form you add.

This is actually not entirely uncommon - sometimes students who start to get really heavy into construction, when the concept itself starts to really click for them and they grow to appreciate what it can do for their understanding of 3D space, will end up focusing on it to the neglect of other important points. At the end of the day, these exercises are quite time consuming, because there are many things that demand our time - and when we realize just how powerful construction can be, we can be prone to forgetting just how much observation matters as well. This causes us to work more from memory.

While there's not a lot of additional advice I can offer on that (it's really a matter of investing more time in that area, where it's currently being neglected), I do encourage you to revisit this section from Lesson 2.

Continuing on, there are a couple things I want to mention in regards to your use of additional masses, which should help you improve your use of this tool.

• First and foremost, the silhouette of those masses is paramount - that's what helps to convey how they actually wrap around the existing structure. One thing that helps with the shape here is to think about how the mass would behave when existing first in the void of empty space, on its own. It all comes down to the silhouette of the mass - here, with nothing else to touch it, our mass would exist like a soft ball of meat or clay, made up only of outward curves. A simple circle for a silhouette. Then, as it presses against an existing structure, the silhouette starts to get more complex. It forms inward curves wherever it makes contact, responding directly to the forms that are present. The silhouette is never random, of course - always changing in response to clear, defined structure. You can see this demonstrated in this diagram. I've also shown some of this in action here on your cat construction. Note how every corner, every inward curve, etc. is placed very specifically, based on how the mass we're adding wraps around the existing structure. Thus, planning our marks out carefully is critical - I definitely noticed a lot of places where your corners were a little off, or where your marks may have been drawn too quickly, without enough planning/preparation. Be sure to use the ghosting method in its entirety.

• Avoid adding contour curves to these additional masses. Basically, there's two main ways in which we can build up more forms onto a construction. In the case that the form wraps around the existing structure, we use the silhouette and only the silhouette to convey that, and in the case that the new form interpenetrates the existing structure, we define that joint with a contour curve, just like we do in the sausage method, between the individual sausage segments. There are places where you place contour lines along the surface of some of your additional masses - this is something to be avoided. It does not actually do anything to establish the relationship between the different forms, it merely makes that individual form feel more solid in isolation. While this is in itself harmless, it actually can be harmful - I've noticed more and more of late that students who get in the habit of using these extra contour lines will feel like they can use them to "correct" the incorrect silhouette design, making them less likely to take the time and care they need in drawing the mass in the first place.

The last thing I wanted to touch upon for now is head construction. Lesson 5 has a lot of different strategies for constructing heads, between the various demos. Given how the course has developed, and how I'm finding new, more effective ways for students to tackle certain problems. So not all the approaches shown are equal, but they do have their uses. As it stands, as explained at the top of the tiger demo page (here), the current approach that is the most generally useful, as well as the most meaningful in terms of these drawings all being exercises in spatial reasoning, is what you'll find here on the informal demos page.

There are a few key points to this approach:

• The specific shape of the eyesockets - the specific pentagonal shape allows for a nice wedge in which the muzzle can fit in between the sockets, as well as a flat edge across which we can lay the forehead area.

• This approach focuses heavily on everything fitting together - no arbitrary gaps or floating elements. This allows us to ensure all of the different pieces feel grounded against one another, like a three dimensional puzzle.

• We have to be mindful of how the marks we make are cuts along the curving surface of the cranial ball - working in individual strokes like this (rather than, say, drawing the eyesocket with an ellipse) helps a lot in reinforcing this idea of engaging with a 3D structure.

Try your best to employ this method when doing constructional drawing exercises using animals in the future, as closely as you can. Sometimes it seems like it's not a good fit for certain heads, but with a bit of finagling it can still apply pretty well. To demonstrate this for another student, I found the most banana-headed rhinoceros I could, and threw together this demo.

Now, I've given you quite a bit to work on, so I'll assign some revisions below.