kinetic typography tips?

I want to try my hand at a kinetic typography video. I guess this is the name they're giving to the MK12-like videos which are animated almost entirely by text on the screen.

Here's two (non-MK12) examples:











Any obvious tips I should keep in mind before diving in? I plan on making each line/phrase its own pre-comp and then assembling them all together in the end. Just to keep things clean and more "one step at a time"ish. But of all the programs I learned in college, I've spent the least amount of time in After Effects.

Thanks in advance.

Alan | www.fallofautumn.com