Mostly Sideways Baby Mittens
These mittens incorporate much of the same shaping and ideas from the adult-sized Mostly Sideways Mittens, but don't have thumbs. Apparently, babies struggle a bit when getting dressed, so leaving the thumb out of a mitten gives you one less tiny thing to worry about. Sizing, as usual, is a bit tricky, but they are garter stitch, so are very stretchy.
Our adorable baby model is about 5 months old, so I'm going to say that the pattern would probably fit babies up to about 6 months old.
I also borrowed an idea from Christine's Stay-On Baby Booties and used a row of eyelets and a drawstring to secure the mittens for baby's wrists. My sister kindly crocheted the strings for the prototype, using the second set of instructions from this website. I, myself, cannot crochet, but I will attest that trying to braid sock-weight yarn caused my hands to cramp in about 5 minutes. So, I would say either go with ribbons on this one, crochet a cord, or make i-cord. Although, frankly, I did not attempt i-cord with sock yarn, so I don't know if that is a recipe for disaster and frustration.
Janet Szabo was kind enough to talk with me about her books, her long-running Twists and Turns Newsletter, and a whole whack of cables.