The key to working clean, perfect crochet post stitches is making sure you don’t have them placed near the beginning or end of a row or round. I specifically designed this crochet cardigan so the shells are at the beginning and end of the rows so I didn’t need to fuss with chains at or around the post stitches.
The closure for this crochet sweater is a set of simple chain ties. You could always add buttons—the holes in the lace fabric would work for buttonholes if you shop for the right size. But the beauty of the chains is simplicity. I like how simple and sweet the ties look in a bow, but I love how it looks if you lace it up a few inches.