You are correct in one thing - fixating on your own sense of satisfaction, at least in the context of these exercises, is a waste of time. It's for the simple reason that what you value and prioritize in these drawings is not necessarily what the lesson itself is focusing on. You will be free to determine your own priorities when you do studies on your own, outside of this course - but when you sit down to work on your Drawabox assignments, focus only on following the instructions, applying them to the best of your current ability, and completing only the assigned number of pages.

To that point, your drawings here are largely quite well done. While it may be tempting to focus only on the weaknesses you perceive, it leads to a skewed impression of your own work, and an unawareness of your strengths. We're often taught that this is ideal, that the best do not concern themselves with what they've achieved - only what they've yet to accomplish. This is not sustainable, nor is it accurate, or truthful. In order to grow, we have to be aware of both - and so whenever you feel dissatisfied with your work, take a step back and ask yourself what you did well.

The main focus of this lesson comes down primarily to precision. Precision and accuracy are often terms that are conflated, but they refer to different things. Where accuracy can be measured based on how close we were to having our mark start and end at our intended points, precision comes down to having plotted out those start/end points prior to executing the mark in the first place. It's based not on the execution of the mark, but rather the steps we take beforehand to plan and declare our intentions.

In this lesson, we achieve this through the subdivision of our bounding box, to specifically mark out where along our structure certain elements should fall, rather than approximating or eyeballing them. So for example, these plug prongs were drawn using the mirroring techniques shown in the lesson notes to specifically maintain equal measurements in 3D space for each one. Certainly there is room for improvement, specifically in how each of the lines themselves were oriented (you definitely need to work on being more mindful of how your lines all converge together), but we practice that through exercises like the rough perspective from Lesson 1, and the boxes (and the line extensions that follow) from the box challenge which should continue to be practiced in your regular warmup routine - it is not a concern for this lesson.

There are some areas where your precision suffers at times, but it really just comes down to how much guesswork are you relying upon. For example, this USB port on the same object is well centered by placing your corners along the diagonals, but its vertical position along the surface of the object is approximated. This is an area where precision could be improved by identifying how far along the wallwart the port sits, and making the appropriate subdivisions.

Before I continue, I want to quickly address your first question, and unfortunately there's no simple or easy tip or trick here. We simply need to take the time to ensure that our marks are converging towards their intended vanishing points. The fact that we're allowed to use a ruler in this lesson does help - the ruler acts as a live extension of the line we're intending to draw, and we can actually see how it projects out towards its intended vanishing point. The correct course of action is to simply take more time to think through how each line should be oriented, and what other lines it's meant to converge with. The plug prongs I mentioned before were indeed a great example of using the mirroring technique, but their alignment is certainly off. Assuming you were using a ruler, this could have been avoided by simply making fuller use of what the tool offers you.

Forgetting to mind things like this - and forgetting to practice those warmup exercises I mentioned earlier - can often occur when we get too preoccupied with how satisfied we are with our drawings. That same dissatisfaction can distract us from the fact that our drawings are, each of them, just 3D spatial puzzles. Matching the reference perfectly isn't a concern - rather, we just use it as a source of information. I believe I mentioned this in regards to your Lesson 5 work some time ago, although we can still see a couple small instances where you allowed your focus on matching the reference to attempt to correct mistakes, as seen on the left and right edges of the wallwart/USB plug.

Ultimately, every mark we put down as part of our construction is an assertion, and a commitment, and they cannot be undone or ignored, once the marks have been put down. Similarly, something we should avoid (although admittedly I make this mistake in the computer mouse demo myself), is pushing beyond the boundaries of the supporting structures we've laid down - for instance, the trigger on this spray bottle which sticks out of the bounding box. The correct course of action here would be to simply cut it off.

Looking at that trigger, I can see that you went to some lengths to lay down an amount of structure for the curve. This is good to see, although I would have still liked to see the trigger itself first defined with a series of straight edges, creating a boxy structure that would only be rounded off towards the end as seen on the handle for the mug in this demo. When building up geometric structures like this that feature curves, always start out with straight edges.

The last thing I wanted to mention - which I usually touch upon at the start, though I was somewhat derailed from my usual flow by your points about being unsatisfied with what is largely solid work - is that your form intersections are coming along exceptionally well. You're demonstrating a strong grasp of how those forms relate to one another in 3D space, as defined by the specific intersection lines themselves. You're even handling the intersections between curving forms quite well, and that is something that is often still a lingering challenge for students at this point. Just one thing - don't forget that in this course, you are required to draw through all ellipses that you freehand two full times before lifting your pen, as discussed back in Lesson 1.

So, I'll go ahead and mark this lesson as complete. In the future, make sure that you only complete the assigned quantity of work, doing so to the best of your ability, and of course keeping up with the previous exercises as part of your warmups. I'm not necessarily saying that you aren't - only you know that - but if you are, make sure that you work on those freely rotated boxes from the box challenge.