I've picked up my copy of Getting Things Done again recently in an effort to get a handle on lots of things in my daily responsibilities that I don't have a very good handle on. I feel as though I have a much deeper understanding of some of the principles of the process this time than I did in my last read of this book. First, I didn't understand how to use my project list to continue to drive my next actions list. I kept trying to figure out how to connect the two together with a 'pointer'. It turns out, if I just forget about that problem, it solves itself. I suppose the brain is happy to continue to connect things so long as you aren't busying it with all the things you need to be worrying about and doing right now.
I've gone low tech in my current implementation with index cards in a 'Hipster PDA' fashion. We'll see how long I can keep it up.