Having someone watch me. Works four out of five times. From talking to other people it has a much higher success rate, but I'm still trying to figure out what's akrasia and what's an executive functioning deficit resulting from minor frontal lobe damage.

I have a friend who hires people to sit across from her at work. Pays for itself with the extra work she can get done.

Stepping back and watching the meat-I-am start to do stuff helps too, but not nearly as often, and I only learned that trick a few weeks ago -- from this site.