I measured (and re-measured) and calculated (and re-calculated) and cast on last night for the Bed Shrug. Then I ripped out. My intention is to do the shrug with picot cuffs instead of the ribbing. I don't feel like the ribbing is "fancy" enough for wedding attire, and the picot edging is girly, without being "ruffly". Thing is that with me only casting on 53 stitches, (which is what I get gauge on in the lace) the mainly stockinette picot edging will never be as stretchy as the lace, I would need almost a third more stitches!
So, my solution is to knit the lace first and block it. Then do a stockinette gauge and determine how many stitches I'll need and pick up that many stitches for each cuff, then knit those on. It's more work, which means more room for error, but it actually seems like the only way to do this without running the risk of teeny tiny cuffs or big billowy backs. Ahhh, alliteration.
Anyway, I will cast on again for the lace part tonight, and post photos of how far I get...wish me luck!