3- and 4-point perspective practice.
I really need to read deeper into this topic, because it seems quite difficult for me and every time I was trying to draw I suddenly had a bunch of questions of why something needs to be done this way and not another, etc.
But I got myself some perspective study books so I plan to read more about it in the meantime of doing terms. I believe it'll help me more with creating some nice environmental drawings in the future ^^
Also as marc suggested, I've tried to make some structures using this perspective but I'm not sure if it looks good Maybe a bit XD.