I really enjoyed this exercise, even though it' quite difficult and I have a lot to improve. I understood that for drawing from imagination, intuitive perspective and visual memory are probably the most important things or at least the first step to do, so I'll continue practicing for a while.

I took some time to do these exercises, I made the drawings several times and this is the best I could do so far. The biggest difficulty I found using construction lines is that mistakes tends to accumulate, so it requires a lot of precision especially in converging correctly the lines towards the vanishing points. Anyway it was very useful to review all the things done so far.

That was very hard but still very useful. A lot of boxes, overlap and perspective. Hope I did it right.

This exercise was quite challenging at the beginning, even thought the human head is kind of boxy is not so easy for me to idealize a box from a head. After a few trial i figure it out my way to do it.