Here is the process I am following for the cast drawing. The board and cast are laid out side by side. A mark is placed on the floor around two meters away between the two. You then stand on that spot and get the basic proportion by drawing the cube. Next you draw lines through the shape to get the form, keeping it as simple as possible. No measuring is done, you relate one line to the other and constantly keep check of the angles. Its hard work but helps train your eye. I have also posted a correction image. I couldn't resist sticking the drawing into Photoshop and overlaying the images to see how accurate I had been........I think I've got some corrections to do!
The next stage will be working in the shadow shape with tone.