Kristina Webb is an amazing artist who came up these super creative drawings mixed with real life elements giving it a nice 3D look and mind blowing style.
I've been seeing these in the web for some time now. David Jablow has come up with a super simple, yet awesome project called "Do it yourself Doodler", in which he takes an original, incomplete doodle and starts to make many doodles from it.
These are a great example of how a person might practice their drawing skills. Do it yourself too! I bet that doing something like David will get your creativity right on date. To get to know more of his project, you may visit the project site, or check out his flickrstream for more of his great doodles! I hope you enjoy these. Chees! ;)