Nobody told me that you basically have your period for weeks after giving birth. Breathable, full-coverage postpartum underwear — especially disposable kinds — are a lifesaver.
A high, wide waistband with gentle compression can help support your core as well as reduce cramping and soreness as you heal.
Postpartum underwear in stretchy materials will be able to comfortably hold ice packs and maternity pads — there's a good chance you'll need both for soreness and bleeding.