I've done some more blocks for The Babette and I've got a plan for finishing all the blocks. See the big block on the top left and the block-in-progress on the lower right? Those are (will be when they're finished) the biggest size of block. In fact, those are the last two of the biggest size of block. Then I will finish all of the next size and so on, until I get to the smallest size. Since the bigger blocks need more of a variety of yarns, I think that by doing those first, I'll have enough different yarns to make them interesting. Then when I'm on the tail ends of the yarns I'll be doing the tiny little blocks which take hardly any yarn at all.
This plan should also make me feel like I'm accomplishing something on The Babette instead of just wandering around aimlessly making blocks.