I finished joining all the blocks in the Be of Good Cheer sampler. The flat braid join worked just fine, and despite the difference in stitch counts among the blocks, it seems to have evened out well enough. I'd definitely use the flat braid join again.
In between joining blocks, I considered what to do for the edging. I bookmarked a few borders in Edie Eckman's Around the Corner book... Then I happened upon this neat edging that mimics the look of the flat braid join: Reproducing a Braid Join Around an Edge. (I'd give better credit, but I found it on Pinterest and am uncertain of the designer. The site that hosts the PDF seems to have nothing to do with crochet at all, so it's a bit of a mystery.)
In the end, I decided to stick with the cute pom pom edging I mentioned last time. The flat braid join left the "unfinished"/unjoined sides of the blocks with all these chain-space loops, so I'm using them as places to anchor the pom pom loops (with single crochet). The pom poms are a time-consuming border to crochet, but I think these pom poms are the perfect icing for this particular cake.
I haven't forgotten the quilt, but now that I'm in the home stretch of this afghan, it's best to avoid distractions. ;o)
Photos next time-- maybe of the completed afghan!