When I draw a box and draw a line badly so I miss the point where I wanted the line to be, should I when extending the lines with color to check convergence, draw through the point and therefore the line I wanted to make or the line I have actually drawn? Because I already know the badly drawn line is off and it wouldnt really help me understand my thinking of the vanishing points when I extend a badly drawn line where the convergence is just off because I have drawn the line badly.

Depending on the type of Box I draw, a line being of by just 0,5mm can sometimes make my convergence go of the chart but when I draw through my actual point it shows that if I had drawn the line where I wanted it to be, they would have all met at nearly the same vanishing point. So drawing perfectly accurate on point without a ruler is for me a bigger problem in this challenge then actually thinking about the 3D space, which in my opinion would miss the actual point of the exercise.