Jamie,
I think the answer to following up is for you to put the types of items you mentioned on your @Waiting For list and review that list once per week. I would also suggest having the other person give you a date by which you can expect them to do whatever it is they are supposed to do. That way you can wait until their self-imposed deadline has passed before following-up. Secondly, it sounds like other people in your life need to read David's book! The better they become organized, the less time you will spend following-up on them.