Hey :)

Here's my critique

Arrows

You're doing a great job here, the lines are confident and the arrow width increases/decreases consistently. The most obvious problem is the accuracy of the line weight and shading, but that will come with time. The best advice I can give you here is give each line as much time and care as needed.

Another problem is that your arrows are flying horizontally across the page a bit too much when they should be going back in 3D space. There is not enough overlaps, sometimes almost the entirety of the back of the arrow should be covered. Here's an example.

This isn't a critique but rather a suggestion, if you want you can exaggerate the size variations of the arrows. You can make them so large that only a portion of them fits on the paper. I think it's beneficial to do this as it enhances your 3D skills. Example

Leaves

Your leaves look nice, however you're not always following the scaffolding you laid down. Some of your leaves extend past the construction line which makes that construction line obsolete. Always follow the construction line (even if it ends up looking off) because on more complex objects you'll lose the sense of 3D space as every deviation from it results in flattening your drawing. If you think the construction line is way off, just start the leaf over.

I like how you did the silhouette texture, keep it up! Not quite sure what the two right-most leaves are supposed to look like. If you find yourself using too many lines, you might wanna rethink how you do the construction for that leaf.

Branches

You're using way too many ellipses here. This goes for anything in art really, ask yourself "what's the least amount of brush strokes I can do to properly convey my drawing?" The answer usually results in the most pleasing looking image. For example, if you have a slight curve on a branch (like the ones on the top), all you need is three ellipses. Two for the start and end and one in the middle. If you'd have a significantly curved one, you could probably pull it off with four ellipses.

Plants

I'll refer to the plants with the convenient number you put on the top of the page! :)

I think you did well here. Your construction feels solid and your plants feel 3D. I'll just list random mistakes as I spot them, they're in no particular order.

(6) I think the cactus texture should vary a bit more. I suggest adding deeper cast shadows as the circle-like forms go further from the light, and maybe even just leaving some of them at the top almost blank, up to the viewers to imagine.

(4) The underside of this plant is kinda confusing. Since we're drawing through the forms it's hard to tell if the bottom side is facing towards or away from us. Of course it's obvious upon further inspection, but I still think you should add some line weight in the front to clarify.

(8) I'm not sure what the plant in the top-right is. I think some silhouette texture could clear it up if the reference had any. I like the way you did the texture on the bottom right one!

(1) Same line weight problem as in (4). We're looking from under the mushroom, right? If so, I suggest adding line weight in these areas. Also, make sure that the ellipses on the branch of the top-left plant turn towards us in a consistent pattern.