Over the semester break, I'm learning to vector-draw ponies! Here's my first one. This was done in Illustrator CS5, traced from a snapshot near the end of "Swarm of the Century". Time: about 3.5 hours.
* Rainbow Dash is hard to draw. Lots of little pieces. Start with Derpy next time!
* The Brush tool makes it easy to lay down variable-width strokes, but hard to adjust them later. Be wise to its ways; the Pen tool makes things much simpler.
* When drawing multicolored hair, forget about drawing the outline first and then filling it with strokes of color unless you're willing to go nuts with the clipping masks. You're way better off tracing the strokes, getting them to fit together, and then making a copy of them, Pathfinder -> Unite, and put a stroke on the amalgamate.
Any advice or guidance from other vector-inclined bronies is appreciated!