Here’s an easy tip to improve Flash’s basic drawing tool, the paintbrush: dial down its automatic smoothing feature. This makes each stroke more faithful to your original drawn line, avoiding the stereotypical “Flash look.”

A potential drawback here is that less smoothing means more complex vector shapes, which make for bigger files and demand more CPU power during real-time playback. However, in many cases this shouldn’t make much difference to a modern computer–and if your project is going to end up exported to video anyway, there’s no excuse not to get the best-quality line possible.

So, while the Paintbrush is selected, open the Properties panel and adjust the Smoothing amount to taste. The default value is 50; I use 20.