Jumping right in with your form intersections, your work here is generally pretty good, and you're definitely demonstrating a well developing understanding of how these forms relate to one another in 3D space - not just limited to the simpler relationships between forms with flat surfaces, but also with the intersections involving flat-and-rounded surfaces, as well as those involving two rounded surfaces. I have just two things for you to keep in mind:

• Use the ghosting method for all of your freehanded linework, and when drawing these forms be sure to remember to engage your whole arm from the shoulder. I'm noticing cases where some lines get a little wonky, where some ellipses aren't quite evenly shaped (especially the spheres, which are definitely difficult, but that means you need to be that much more attentive to how you're using your arm to give yourself the best chance of executing them successfully). In general, it does seem like you may have forgotten at times to go through all of the steps of the ghosting method in a consistent manner. It is of course time consuming, but it is your responsibility here to give yourself as much time as you require to complete the work to the best of your current ability.

• When drawing intersection lines, it can at times be helpful to break them into sections. This already happens naturally when dealing with flat-on-flat intersections, where we'll hit an edge and the trajectory of the whole intersection line will have to change, giving us an opportunity to lift our pen and plan out a new stroke. With the more complex curved-on-curved intersections however, it's still a good idea to draw each curving portion separately, stitching them together as shown here, so that when we draw each segment we can focus entirely on how it's supposed to follow the surfaces of the forms.

Continuing onto your object constructions, I can definitely see that your understanding of the material, and how the techniques demonstrated here can be leveraged, growing steadily over the course of the homework. In particular, I can see that you're steadily considering different ways those building blocks and techniques can be used to build up your objects, where you position different forms, and so on. There are however some areas where I can provide advice to help you continue to improve your understanding of how these tools can be employed to their best effect.

First off, remember to pay attention to your convergences. As we can see here, this spray bottle has some extremely parallel lines for its verticals (and I expect that if we extended out those in the other dimensions, they'd be similarly parallel. This is actually an issue I remarked upon in regards to your cylinder challenge, and for which you were assigned revisions - so I strongly urge you to go and review that feedback to better understand why this is incorrect.

Before we move on from that topic however, I want to mention that while some students may incorrectly try to force vanishing points to infinity to simplify the problem at hand (by eliminating the convergences on one or several axes), you actually already have a tool at your disposal which is allowed in this challenge to help with this: your ruler. A ruler is not only useful for ensuring our lines are straight, they actually give us a clear, visible extension of the line you wish to draw, without ever committing to a stroke. Meaning that you can put your ruler on the page, see where that line's going to extend towards, and adjust that alignment to ensure your convergences are generally consistent. There's no need to simplify the exercise in a manner that breaks the rules of perspective.

Secondly, boxes are an excellent tool when it comes to positioning forms in space - so don't be afraid to use them for everything, even where it may seem unnecessary. For example, the knob at the end of the rotary handle of this object. Ideally you'd be establishing a box for the whole structure, with planes set for every curve you placed. Inside those planes you'd draw full ellipses, establishing the entire cross-section of the knob at that point to develop the whole form. Here you ended up taking shortcuts by just relying on curves, and in so doing you missed a lot of the structural integrity to make it feel entirely solid. Similarly for this part, that structure ends up floating more loosely inside of the larger box enclosing it. The best way to ensure everything is solid is to keep all of your spatial relationships tight and specific, and avoid any kind of loose relationships where something feels like it's floating within another form.

To that point, keep in mind what's explained here in terms of building up all of your curves with chains of straight edges or flat surfaces, in order to lay them out more specifically, only rounding them out towards the end. This could have helped as an intermediary step when establishing the headstrap of these headphones.

The last piece of advice I wanted to offer has to do with the use of orthographic plans. Instead of explaining it here however, I'm going to point you to this section which I actually only added to the lesson last week, so it would not have been there when you were going through it. It does however include an explanation as well as a lengthy demonstration showing how those orthographic plans can be leveraged to construct objects, both for this lesson, and for the vehicles we deal with in Lesson 7.

All in all you're certainly progressing well, but there's a lot that can be pushed further, so be sure to continue to keep these points in mind and to practice them on your own as you make your way through to the end of the course. I'll go ahead and mark this lesson as complete.