Dresses were my favorite when I was in that first postnatal phase after having Owen, and they are this time around as well. Look for empire waisted, soft fabrics that don't cling to your tummy. Bonus points if you can find dresses with detail like the ruched neckline of the one above. A little detail can add just enough visual interest to make even the simplest summer dress special.
Gladiator sandals are still my favorite type of footwear for summer, and unless you're dealing with postnatal edema and swelling, they'll likely become yours too.
For accessories, think big floppy beach hat, structured fedora, or open weave cuff and long necklace like the ones pictured above.
Ultimately, you want to be comfortable, but feel human again!