@ Ceru
Copying great artists has been used as a method of improving drawing skills for hundreds of years. With current copyright laws in place, however, I would recommend against taking your favourite artist on DevArt as a model. Go for the classics. Or, if you like cartooning, then look at Marvel and DC comics (or whatever franchise you prefer).
Better yet, look up photos of Greek statues, or sculptures done by Michelangelo and Raffaello. Try to reproduce those. Or, go to your nearest art gallery, set up shop there, and sketch the paintings on display. No need to go into detail, just try and capture the essence - that would be a quick sketch. The idea is to train your hand, so that your pencil/brush strokes become more stable and confident.
Art has always been a hobby for me, but I did receive classical training. It's pretty gruelling, but it gives results very quickly. I started out with drawing only shapes - just lines, no shading, no planes, no nothing. My prof's words: "Do not draw an apple for me, draw this apple for me."
Then I went on to division of planes, then finally shading - all of this is still life. For human anatomy, I drew the skeleton as a whole, and in parts, as well as the muscles. Then started with figure drawing and a live model. For portraits, I was asked to draw individual features over and over and over again (eyes, lips, nose front, side, and 3/4 views). Then finally I could attempt a portrait. It took some time. However, I improved in leaps and bounds. In a mere 6 months, I was able to accurately reproduce Greek statues.
Oh, and then there was perspective as well... and composition. Those were a lot of fun, actually 
Aaaanyway... Keep it simple, and have fun 