My usual self-testing example is something like "can I write this program correctly on the very first try?". That's a hard challenge, integrated into my everyday work.

I should try to remember to try this the next time I have a short piece of code to write. Furthermore, it's the sort of thing that makes me slightly uncomfortable and is therefore easy to forget, so I should try harder to remember it.

In general, this sort of thing seems like a very useful technique if you can do it without endangering your work. Modded parent up.