THE SKELE-PROCESS!

I noticed that George Lucas has no qualms about revealing his secrets. To him it doesn't really spoil the final product—and at the same time it might inspire some younng people to be creative if they recognize that all that magic is actually done by mere mortals. Not that I approach anything close to Lucas' work, but...

A lot of work goes into the modern skeleton...but anymore the hardest part is inspiration; from my perspective, they get better all by themselves. Of course it's me doing the learning, but anytime you practice something you get better at it rather deterministically, except for those areas in which you are consciously trying to modify your approach—in which case your learning can take some drastically new directions. But I digress...

Let's take a look at a skeleton from start to finish:
     

First of all, I'm bored at work and decide to doodle something on a whiteboard, in this case, a "sword-weilding skeleton!"

Then of course, the REAL artist who works with me has to do a spoof of my skeleton...

I smile and nod my head, and then quietly toss his skeleton in the trashcan because it's not a REAL skeleton. :)
Next I clean up the photo, filling in some pure white so that I have a good archetype to work with:
With the modern process, the only part of the original image that I actually keep is the face—without it you lose some of the cartoonish quality. The rest of the skeleton will be traced.
Next I trace the hand-drawing with 3D shapes...polygons for the head and spine, pipes for the ribs and arms.
Smoothing out those sharp edges from the 3D rendering by converting them to flat bitmaps and brushing them until they're good and smooth...position and size the face...
Tracing the entire skeleton in like fashion...adding objects and what we call "movement marks" in the biz...
A nice background and some effects and suddenly the skeleton exists in some kind of world!
Grab one of the templates used for the card container:
Set the caption, colors, and insert the picture!
 
Ok, so maybe I've omitted some of the headaches that occur along the way...but this is the basic process, evolved over hundreds of skeletons. Now go be inspired! :)