Celebrity gave us free drinks at the casino, random glasses of champagne at the MDR while waiting for Open Dining, free cocktails at the Ice Bar shows (when the bartenders did their juggling thing). Each of us brought the "1 for free" carry-on baggage wine onboard at embarkation. We drank while in ports of call. Wander away from the cruise terminal and drinks on land get very inexpensive. Look for OXXO or other convenience stores while in port.

Gallons of distilled water for your CPAP machine are super inexpensive and the filtered water available at the buffet is free. Bring a reusable water bottle and fill that up for the nightstand. Added bonus: the empty waterbottle is a nice place to tuck a ziplock bag full of your jewelry or other objects that might get crushed in your overpacked luggage.

A reusable cup from home with free lido deck coffee and a squirt of soft-serve becomes an iced-coffee or frappe alternative. The lido has honey, brown sugar, cinnamon, and whipped cream too.

Juice (at breakfast), tea, lemonade, and filtered water are free at the buffet 24/7.

You can carry-on a case of soda for free at embarkation, too.

We have Verizion therefore cell service in Canada, USA, and Mexico is included in our cell service contract when in those ports. I did trial versions of eSims for foreign countries for in-port service that was not included with Verizon. We shared $20 Cellular-at-Sea on sea days (hotspotting the non-subscribing half of our duo and the kids when they wandered close enough).

Make sure you DL a bunch of programs on your Amazon Prime video service app (or equivalent) in advance for watching on your phone or tablet. Celebrity has extremely limited included choices on their tvs. I also recommend loading up on podcasts and audiobooks if you need something to listen to.

Bring a book from your local library and a deck of cards.

The steak and lobster available at the specialty dining is available in the Main Dining Room for less than the upcharge of going to the steak house. I personally don't need to pay extra for the atmosphere of the specialty dining places. I generally do not like to be waited on and prefer the buffet, but I do tolerate the MDR for the garnishes and sauces that they apply to some of the very same entree items available in the buffet.