Hello, Rodri:

I will be reviewing your work today.

Arrows

You got good results there. Try to make more "width changes" when you are practicing with these exercises. Maintaining a consistent width while doing parallel lines is one of the goals of it and it could help you with your branches too.

I think that you can improve the arrowheads with a little bit of planning. Right now most arrowheads seem to point sideways and that contradicts the entire flow of the arrow. Just imagine a line that is in the middle of the arrow following the flow of it and place a dot where you want the tip of the head, it's a similar process to the one used in the leaves exercise.

Leaves

They are good enough. I think you could have explored more with twisting the leaves so I recommend you to try it out in some warm-ups if you can.

Outlines feel a bit plain, especially the bottom right corner one. When adding detail to the silhouette try to make specific decisions on each stroke, you have to visualize what you want to construct from it. The added form should follow the general motion of the entire construction. In this specific case, the central flow line marks a bending away from the viewer, but the spikes on its right are diverging from that flow and bend towards the viewer. It's not that big of a deal because you could be wanting that bending too but I pointed it out in case you didn't.

Branches

You probably need more practice in the fundamentals that this exercise builds on top of. Some ellipses are misaligned with the central flow line and your lines were not confident sometimes.

I think this is just a lack of practice, try to warm up with organic forms more often. Drawing more branches should help for sure. Also, try to apply weight to your lines more often because that's extra practice for this kind of construction.

Flowers

All of them were pretty good. The previously mentioned problems destroy a bit of what you build but the results still maintain that feeling of solidity and 3D. I think you were sometimes afraid of crossing the sidelines of the leaves while trying to twist them, don't worry about making a mess, and cross both lines when you need it to maintain a proportional consistent width.

Also when applying line weight remember to use it sparingly. It's not about making the entire line thicker, but only a segment of that line that needs extra information to tell the viewer it's closer.

Verdict

You are good to go. Try to warm up mixing the branches exercise and leaves exercise because your main problems were related to misaligned ellipses, not crossing sidelines while rotating leaves, and lack of accuracy while joining ellipses.

I think you got all the concepts and practice will do the rest.