Hello Lupurisan, I hope you are well

Starting with organic forms:

Those are made quite well, you make them simple with both ends the same sizes.

But quite often you aren't changing their degrees, remember that when ellipse gets away from us its degree becomes wider.

The next thing that I want to point out is that sometimes you arent hooking the contours enough, quite often you hook only one end.

There are places where your lines are quite sloppy. Keep in mind to take as much time as needed for ghosting and when it feels right, execute the line in a single stroke with the upmost confidence.

Insects:

You draw them really good, but the thing that stands most to time is that your linework and lineweight on legs could see some work. As it stands now, your lineweight makes them really flat. So for lineweight remember to also ghost for that process. What we want to do is add another line on top of our initial one and what we should get is an effect of our line becoming darker(as we give more ink to the line) and slightly wider(as ink spills slightly to the sides). Making our line wider isn't our goal, it is to make it stronger/darker. This diagram conveys what I am trying to say.

It could be also your linework, don't repeat your lines, even if you made a bad line, leave it and treat it as if it was the correct one. We don't want to correct our lines as it starts bad habits and teaches us that we don't have to commit to our lines. Leave your bad line there to be seen. Next time you try to make a line, don't repeat the same mistake you did the previous time.

I like your house fly 3, it isn't perfect but it does have a fair number of really confident lines that reinforcement 3d feel of that drawing. On the subject of that house fly, you don't emphesize the segmented abdomen enough, it feels 2d, you need to make those segments go outward a little bit more. Another thing that doesn't help is again your quite messy lines.

With shadows and lineweight we want to show which masses are on top and which aren't. We don't want to strengthen every line we made previously with lineweight, this is called working in passes. We don't do that in drawabox. We want to carefully construct our building block and then help the viewer with overlapping form through shadows and little lineweight.

Conclusion:

Your sausages are good, no need for a redo in that part.

For you insects, I would want you to make another 3, no need for texture. Keep in mind what I wrote and mostly take your time and be patient with every line. Don't overdo the lineweight and repeat your lines.

If you have any questions feel free to write to me.