Starting with your arrows, these are looking good. You've drawn them with a great deal of confidence and are capturing a strong sense of fluidity in how they move through all three dimensions of space. That carries over pretty nicely to your leaves, which have a similarly confident sense of fluidity, capturing not only how they sit in 3D space, but also how they move through the space they occupy. From what I can see, you're also doing a good job of adding edge complexity, building it on one little piece at a time, rather than with a single continuous zigzagging stroke.

One thing to experiment with in the future are more complex leaf structures.

Continuing onto your branches, for the most part these are well done, although you're not consistently extending your segments fully halfway to the next ellipse as explained in the instructions. You do it pretty often, but it doesn't appear to be entirely intentional - so I definitely wanted to draw your attention to this requirement. It helps make the transition from one segment to the next smoother and more seamless.

Moving onto your plant constructions, your results here are a bit of a mix. As a whole you're doing a pretty good job of handling the construction and core structure (this one is really well constructed, for example), which is the most important part of the lesson, but when it comes to approaching the detail side of things, I think you're running into a number of issues.

The first point to make clear is that when you're get to detail, you seem to think of it primarily as an opportunity to decorate your drawing. This isn't correct. What we're doing in this course can be broken into two distinct sections - construction and texture - and they both focus on the same concept. With construction we're communicating to the viewer what they need to know to understand how they might manipulate this object with their hands, were it in front of them. With texture, we're communicating to the viewer what they need to know to understand what it'd feel like to run their fingers over the object's various surfaces. Both of these focus on communicating three dimensional information. Both sections have specific jobs to accomplish, and none of it has to do with making the drawing look nice.

This means that we need to keep this goal, of communicating the information that we'd feel with our hands rather than see with our eyes, in mind at all times. Furthermore, there are restrictions - like what we discussed about not getting into any form shading back in lesson 2 - that must be adhered to for the drawings you do here. It's very easy to get a bit preoccupied with putting down those big solid areas of black, without necessarily thinking about what is creating them (as you did here). Every filled black shape should be used to represent a cast shadow shape - which means that when drawing each of these, you need to always be thinking about how it relates to the form that is casting it.

Cast shadows are also subject to a consistent light source - which means you'll have the shadows cast to the left or right, not both (as you did here in the daisy demo). Also, when it comes to any kind of darker local colours, you may feel tempted to try and capture it by filling in that surface with solid black - but due to our limited tools (we can only draw in pure black or leave things as white) we simply don't have the means to capture local colour. So instead of filling in the veins of your leaves as you did here, it's best to treat everything like it's of a solid white colour.

Stepping back to the edge detail on leaves, you did a great job of it in your leaves exercise, although it seems that here you got a little sloppy and erratic and didn't invest as much time as was required. Make sure you're not rushing yourself through any step - every mark will demand a certain amount of time from you, and you should always be willing to offer it.

Lastly, in this last drawing, you definitely have a bit of a mixture. There are areas where your cast shadow shapes imply a realistic, believable tree bark, but there are others where you get more frantic and impatient, resorting to more scribbling and randomness rather than allowing yourself to be patient and observant. Texture is not something you can get through quickly - if you choose to add it (and you'll find that this course isn't at all focused on it, and will always prioritize the importance of strong structure and construction before ever worrying about detail), you need to be willing to invest as much time as it demands of you. There is no threshold where the student is allowed to throw in the towel and just scribble the rest of the way. Even if it requires you to complete a drawing across multiple sittings, that's perfectly okay. No one is demanding you complete it in a single session - just that you invest as much time as is required to complete the work to the best of your ability.

Now, since your construction is pretty solid throughout the set, I'm still happy to mark this lesson as complete. Just be sure to keep what I've stated here in mind as you move forwards, and maybe tone down the focus on detail. While right now you've balanced it fine, there is a real risk of students getting distracted by the focus on detail and ultimately letting their underlying construction suffer for it.