HEEEEEELP
!!!!
My god, this part of drawing a reference with the proportions right and fitting in the same place is giving me some work!
I haven't figured out a way of marking the landmarks of the reference body in an accurate way, and the way Marc show his explanation is super fast due to his skill, i saw that part of the class like 20 times already but my first attempt was kinda off.
Like this thing of holding the stylus head to measure distances is not working for me in the digital area, and on his videos he used that measurement inside the canvas, almost like a digital ruler ( which if I were to do that sounded like cheating cuz i could measure straight from the body in that case ).
I find that doing the vertical line of the total height and the horizontal line of the total width and doing the box helps a lot, but its still hard to pin point the important landmarks like elbows, hands, knees, sholders e etc... with only the square.
Well here is my first attempt 

And here is with the line ''art'' on top of the reference

My extreme landmarks are kinda ok like the feets and the hands but when i try to drawn from the eyeballing I loose track, as you can see.
Look at that elbow x) jesus !
Anyone have any tips for this exercise please
!