Started the perspective 2 course as well.
Point 3 perspective is something I've always tried to do, but never really got the hang of. With this course, I finally learned something really important.
Keep your 3 points outside the canvas and try to keep your canvas within the are of these 3 points.
It sounds really simple, but I don't remember hearing this before. Most videos or tutorials I saw about it just explained how to use the 3 point ruler and how it works, but not what happens if your vanishing points are within the canvas.
Moreso, seeing the interaction between the 3 points, you can clearly see they are intended to represent the x/y/z coordinates, but I had not seen someone explain to treat the 3 vanishing points as such. Once you do, you can clearly see the effect on the drawing, and how the z vanishing point impacts the angle if you decide to put it above or below.
I'm really happy to finally get these concepts, and though I'm still going through it, I tried to apply it on a drawing for the webtoon, in this example below.