by Michael Newberry
NOTE FROM MSK: The actual tutorial has been removed at the request of Michael Newberry. The link to the tutorial on his site remains in the title above. I highly recommend you go there and go through it. Here is a small quote from it:
Many figurative artists make wonderful gesture drawings in twenty minutes or less. Yet, if they spend more time on the work, peculiar problems of proportions surface. They will often doggedly stick with the gesture technique and feel that over-analyzing is a curse; when, in fact, mastery of proportions is what is needed.
It's virtually impossible to make a detailed, beautiful, figurative drawing without mastering proportions--and proportions are pure math.