Most artists draw tiny comprehensive sketches (thumbnails) before they draw a final. This is so helpful in so many ways, I highly recommend it.
But for those students who want to simplify the form I suggest doing thumbnails AFTER the final. Trust me, you'll learn lots from deconstructing your own drawing.
I Often end up scrapping the final and keeping the thumb.
F.U. Usually a 'finished' piece is a dead piece, this is why Anthony Ryder and people like him do more harm than good to students of the form. So by re-drawing it the size of a thumbnail you'll get some of that energy back and a totally different drawing will emerge.