Starting with your arrows, you're doing a pretty good job of drawing these such that they flow fluidly through space and convey a sense of movement. There are some where you're demonstrating a decent grasp of how the spacing between the zigzagging sections ought to compress as they move away from the viewer, but there are also others where that spacing continues to be a bit more arbitrary - so make sure in the future you're always thinking about how perspective ought to compress those gaps, the farther back we look, and how that should be consistent with the rate at which the ribbon itself gets narrower.

Moving onto your leaves exercise, the first thing that jumps out at me is that your linework is honestly a bit sloppy. There tend to be gaps where lines ought to meet - both when defining the initial silhouette of your leaves, as well as the little contour lines themselves. As a whole, it doesn't look to me as though you're applying the ghosting method to your marks, and as a result they're not as controlled as they ought to be.

Aside from line work, you are more or less following the process correctly - that is, building things up in phases, and adhering to the previous phase as a scaffolding to support any further information you add thereafter - but that line work is definitely a concern that plays a big role in diminishing your results.

Moving onto your branches exercises, I think your performance here is somewhat better, as far as executing your individual strokes. I feel that perhaps because this exercise is more demanding, with longer lines, you're more willing to apply the ghosting method, and more willing to draw from your shoulder. That said, I am noticing one main issue - in many cases, you don't appear to be extending your segments fully halfway towards the next ellipse (as shown here), and instead you often only extended those segments slightly past the previous ellipse. This minimized the overlap between that segment and the next, and resulted in a more sudden jump from one to the next, rather than a seamless transition.

Moving onto your plant constructions, your results are varied. There are definitely places where you're showing a great deal more care with your linework, and others where things get sloppy again. It's very clear that you're entirely capable of being mindful of how you attack each and every mark - for example, for the most part the lines in this drawing are fluid and smooth, and there are minimal gaps where the shapes come together. There are a few places where you seem to have chicken-scratched when adding line weight (we apply the ghosting method here too), but aside from that this construction is quite well done, and the petals as a result convey a strong sense of fluidity.

We see this in the next page as well - your linework is intentional and purposeful, and it's clear that you're putting thought into how you approach each of these strokes. As a side note, when drawing the mushroom construction on the left side, you didn't draw the entirely of the stalk - instead, where the head overlaps it, you basically stopped drawing the stalk altogether. It's important to draw through all of your forms (which you generally do a good job of), so that we can fully understand how these forms sit in space and how they relate to one another within that space.

Now, every drawing after this point falls back into that loose, sloppy linework, and I think it comes down to a simple shift in mindset - with these drawings, you have it in your mind that you're going to get into detail/texture, and as a result, you approach the underlying construction in a fundamentally different way.

There are also issues with how you approach that detail pass - your actual texture tends to be rather scratchy and indistinct, rather than actually focusing on specific textural forms, and capturing the shadow shapes they cast in order to imply their presence.

One major issue with this drawing just comes down to how you think about those solid black shapes. Solid black shapes should be reserved for cast shadows only - cast shadows, by their very nature, need to be cast upon some sort of a physical surface. You however have just filled in the negative space between your leaves, filling in areas that do not rest on any actual surface - they're just floating in the air. The only places where you can ostensibly place cast shadow shapes in this drawing is on the leaves themselves, the flower pot, the dirt inside the flower pot, and the floor upon which the flower pot rests.

For now, I think we need to take a step back and focus entirely on construction, leaving texture and detail aside. I suspect that you're getting caught up in the idea of drawing things quickly, without necessarily thinking all that much about the specific marks you're putting down. This is a common issue, often caused by seeing more established artists and how they can quickly capture the likeness of something in just a few quick strokes. They work off instinct, instinct that has been developed over years of practice. Here, you also appear to be trying to rely on your instincts - except the exercises we're doing here (including these constructional drawings, which are themselves, exercises) are precisely what we're doing to gradually train our instincts. If you use your instincts while attempting to train them, you're going to just end up with a mess.

So, I've assigned some additional pages below that I'd like you to do.