That's great bansheet! Congratulations on the super-vivid, almost lucid dream!

This "in your head" approach is exactly what I do to bring up dream recall as well. I also stumbled across Mastermind's dream recall thread and did some physical daytime journaling whenever my dream recall was down in the dumps. The approach is amazingly effective (at least for me.) But when I found that life was simply too busy to accommodate this new habit, I shifted to mentally running through the day just like you do. Basically, every couple of hours, I replay the last several hours of my day in ultra fast-forward, running through what I did, where I went, what I saw, the faces of strangers that I'd passed... everything I could remember! It's not quite as powerful as the waking journal for me, but it's a great technique nonetheless.

I'm also looking forward to seeing how the physical journal works for you. I love the idea of utilizing meditation and mantras for improved recall but just haven't done much with this myself yet. You're making me want to try it out though! Let us know how it goes for you!