I've been using GTD for about 12 years, and have the Weekly Review installed as an ALMOST weekly event...! Where I fall short (not to some external standard, just to my own intention) is in capturing and downloading what's on my mind, both on the fly, and in the context of a more structured "mind dump."
A lot of times I do my mind dump at the "end" of my weekly review process; at which time I'm often feeling pressed for time. So I don't "let it flow" as well as it could. While I could say, "Well, I guess nothing's on my mind, I'm cool!" I have a nagging suspicion it's just that I haven't allowed myself to dig down quite deep enough.
I also think that capturing ideas on the fly is really the best way to go (being a songwriter, I try to be in that habit anyway), because then there IS no digging necessary -- you're just plucking the ideas out of thin air, almost...
My question? I suppose just a request for other people's experience in dumping their minds. I know there have been posts on "How do you know you're 100% downloaded?" and that's a great question. My question is more...what techniques do you use to let it flow?