I definitely overpacked for the hospital and used very few things I brought! I recommend wearing the same clothes to the hospital that you'll wear home. Besides that, bring chapstick (my hospital provided this), your phone, ID/insurance card, iPad or book or something similar, chargers, extra underwear, gas-X strips, and your favorite pillow.
I walked the hospital in the gown and socks they provided. Never had any desire to make the extra effort to change out of anything lol