So I turned to what I know: knitting!
And then I turned to my all-time favorite knitting book: Poetry in Stitches by Solveig Hisdal and decided to start by making the baby layette she designed.
Et voila, here is the second blank slate:
The third blank slate is that we won't know if one of the babies will be a boy or a girl. So I modified Solveig Hisdal's embroidery design in an attempt to make the sweater more gender-neutral. Alas, I fear it tends toward the masculine at this point, although with a butterfly on the back and picot edging and textured sleeves, it may yet suit either a boy or a girl.