I just remember reading Bruce Lee saying something along the lines of "Even a master must return to his roots often, remembering and practicing the fundamentals." - Paraphrased. I find I am along the same line of thinking. The basic foundations of anything are the basis for great movement when remembered. Sketching, or what I sometimes call doodling, is one of the foundations, drawing from reference offers a very distinct challenge as I attempt to replicate new patterns and understand new structures. It's easy to draw what you've drawn 1000 times, but mimicking the unknown is naturally going to create a more dynamic artist. Keep on challenging yourself and keep on having fun.
A couple sketches of Pocahontas
My Nephew as about the age of four.
All things creative.