Hey there Lars. For now your scale looks good and you should not be having trouble using your shoulder at this scale. In regards to practice between lessons - draw for fun! :D It's important to find joy in drawing and the best way is to make sure you are drawing stuff you want to in between just trying to improve. We also recommend doing these exercises as warmups for 10-15 minutes every day. Now let's get to your critique.

Lines - Your superimposed lines are off to a good start. They are confident and being drawn from the shoulder. You are having some fraying at the ends but as you practice and find a good speed this will tighten up. Your ghosted lines are also doing well being drawn from the shoulder but sometimes you get a little wobbly at the ends. Definitely a really good start and just needs more mileage. For ghosting curved lines - there is no "right way" just whatever way you find works for you stick with that.

Ellipses - Your ellipses are also being drawn confidently and you're drawing through them well, if not one too many passes. Keep practicing on getting those subsequent passes tighter on your initial pass but otherwise things are looking good - no flat areas or pointy bits. Your ellipses in planes are hitting some of the points they should be but not all so there are times where your ellipses are floating in space instead of being snug within the boundaries. Your ellipses in tables however are much more snug and leave no room for ambiguity. You do a good job keeping things uniform within each row, but things are still a little uncontrolled here with your drawing through. You do a good job aligning your minor axes to the funnel axes in your funnels work and you keep things in good contact with the curved boundaries.

Rough Perspective - With your rough perspective you are definitely doing a good job trying to draw your lines confidently and with the shoulder. So much so that you drew larger than the example which has 3 frames per page. I am going to make a judgment call and say that I don't think you were trying to disobey instructions but trying to maximize your use of shoulder, but in future lessons stick to the instructions. The same goes for your organic perspective but I wont reiterate it there. Your horizontal lines are parallel to the horizon and verticals are perpendicular so your boxes are properly oriented to the horizon. Your converging lines are where we expect and as you practice your accuracy towards distant points will increase. Some of your lines get a little shaky and less confident, but overall a good start.

Rotated Boxes - This exercise is hard and meant to be so, that is because the only goal for students here is to finish it the best they can so they are exposed to new types of spatial puzzles and solution methods. You did a good job drawing large to give your brain plenty of room to work through this and all things considered you did a fine job. In terms of rotation, your boxes were not rotating so give this gif another few watches and study how the rotation is driven by the motion of the vanishing points. Additionally, you would have had more success if you had packed your boxes tighter so you could leverage adjacent lines as perspective guides, especially with things like the top left area. Overall though you kept things neat and took your time, it was just a matter of dealing with an extra difficult task. You kept things neat and clear and you pushed through to completion.

Organic Perspective - Your lines are very confident and neat here and drawn with the shoulder so good job. Your perspective is still developing and you have a lot of divergence happening where near planes are smaller than far planes, but that will get worked on in the next steps. Your boxes are all kind of at the same scale so there isn't much feeling of 3d space with a clear fore,mid, and background like you could achieve with scaling down your boxes, but on the other hand all of the overlapping of your forms makes the brain perceive them as existing in the same space which does help them to appear three dimensional. This is another difficult exercise that you are expectedd to struggle with but you did a good job trying your best.

So I'll be marking your lesson 1 as complete. As you move on to the box challenge make sure to follow all of the directions exactly as written. Keep working on ellipse control exercises in your warm ups, and keep up the good work.