We seldom use cash locally. Groceries, gas, misc--on the card. All charities, clothing, haircuts, drycleaning, restaurants, any bills like utilities, phone, wifi, etc. That stuff adds up. All travel cost when possible (no INT fees--we have 2 cards for that use)--plus our tickets. We hardly use the Amex any more, except for the bennies. Still cheaper than SkyClub w/emp discount.
Hope it works for you. Good luck.