This is about a five minute drawing (in reddish chalk) which has been re-stated (in orange chalk) using construction lines in order to capture gesture. Plumb verticals, horizontals and oblique lines were observed and drawn in order to strengthen the sense of proportion and perspective.
The same method was used in this pencil drawing, but for a much longer period of time (about 3.5 hours of drawing in 20 minute periods with 5 minute breaks).
This is after about 7 hours of drawing. 
This is after about 10 hours of drawing. One of the strategies to draw the figure was to use the background window mullions, wainscoting and platform lines, which are true vertical plumb lines, to see where the verticals intersect certain points on the model. This helps in terms of proportion. Essentially it is like having a grid, but this grid is more like a tartan pattern, and the grid can be used to measure and confirm certain points on the model. Its the same idea as Durer's drawing machine which consists of a window sash with strings attached to form an orthogonal grid through which the figure can be viewed and transcribed box by box as needed. Another way to think about it is as a pane of glass through which the model is viewed and traced onto the glass. Here's a picture of durer's drawing machine:
Today we discussed contour and gesture drawing. The class warmed up with five two-minute contour drawings and five two-minute gesture drawings in the spirit of Kimon Nicolaides from The Natural Way to Draw.
Our final drawing was twenty-four minutes.
