Congratulations on completing lesson 3! I'll do my best to give you useful advice so you can improve.

Starting with your arrows, you're doing a great job of executing these with a good deal of confidence, which helps immensely in pushing the sense of fluidity with which they move through the world. This carries over nicely onto your leaves, where you're capturing not only how they sit statically in 3D space, but also how they move through the space they occupy. In addition to this, you're building up your edge detail well, adding each little bit as a separate stroke onto the existing structure, rising off and returning to the existing edge. One quick thing I wanted to point out was that on the top left arrow you attempted to re-do the bottom line, which you should try to avoid re-doing it if possible as all it does it make your work look messier and it brings attention to the mistake.

For your leaves textures, you've done a great job at capturing the shadow shapes for some leaves while others you simply draw lines which leans more towards capturing explicit details. If you take a look at this informal demo https://drawabox.com/lesson/3/8/texture you'll see that most of your leaves only reach step 2 which is just the basic structure to lay down future shadow shapes.

Continuing onto your branches, very nice work! You're generally extending your edge segments roughly halfway to the next ellipse, which allows for a healthy overlap between the edges and allows you to achieve a smoother, more seamless transition between them. One piece of advice I can give for the degree of the ellipses is to try and experiment with shifting the degree more https://drawabox.com/lesson/1/5/degreeshift right now your branches consist of mostly the same ellipse degree which makes them feel a bit stiff and flat.

And finally, you've held to the trend with your plant constructions as well. I can see a lot of attention being paid to the instructions, and the general processes of construction - working from simple to complex - and avoiding skipping steps as that complexity is built up in the vast majority of cases.

I just have a couple things to mention:

For plants 5 and 6 (and some of your previous leaves as well), you should avoid carelessly zigzagging the outer lines https://drawabox.com/lesson/3/2/zigzag once you place down the basic silhouette of your construction you should adhere to it as closely as possible

On plant 3 some of your leaves start to become a bit complex. When laying down the construction try to make it as simple as possible before changing its silhouette

And that's pretty much it!