I did this for , because she needed a little guide on perspective for her school project, and she recommended that I post it here as well, for more people to use. I figured, why not. translated it into English so here you go.
a little overview of perspective basics as well as perspective of human body. very basic stuff because if I started going deeper into this thing, it'd get enormous and I'd probably make a fool out of myself along the way no design for the table because that's not the point.
hope it helps someone. if you have any other questions, or if something's not clear, feel free to ask. in advance, sorry if something's written in gibberish, English's not my mother tongue.
picture at the very top is [The Workstation]. thank you <3 other pictures were done by me
If you draw a cube in perspective, it'll be easier for you to for example plan a pose different than standing upright, and to keep your character's proportions in check. But a 2D rectangle drawn in perspective should be enough for setting a standing position's proportions