"Free" or included sodas are in the dining rooms (& Cabanas) and from the drink stations. If you get a soda from the little kiosk outside the theaters, the Cove Cafe, or room service you'll be charged for them. The Cove Cafe sells specialty coffee drinks that are an extra charge. I think in the dining rooms if you have some of the specialty drinks like the smoothies or coffees those are extra-costs.
We bring our own liquor & jumbo insulated tumblers to mix our own drinks onboard. I love that about DCL: you can carry your own liquor onboard. I don't have to get creative and try to smuggle it like on other cruise lines ((still formulating my plan of attack for RCI's Allure next year...)). Hubby & I are generally good for another drink or two from a bar at some point onboard so we realize it doesn't eliminate the drinky-drink cost but does greatly reduce it. If you are a wine drinker (I'm not) and you want your own wine poured at dinner there will be a corkage fee but I don't know what the amount(s) will be.
You can pre-pay your standard gratuity amounts per the link Flynn referenced. I'm a fan of pre-paying gratuities. Generally we add a little extra to the tip envelope when it's time if the service has warranted.
I liked the tip I got from my trusty-TA about bringing an envelope with a stack of single dollar bills. I use these for tipping porters at the curb and also tipping the servers who bring the room service items (helloooooo Mickey's Premium bars in bed!).
Specialty dining onboard costs extra. If you and the hubby want to go to Palo or Remy it'll be an additional cost as previously mentioned.
Also, if you're gonna do an onboard booking even if it's just a placeholder cruise to switch at some future date you'll need to think ahead for that as well.
Oh! And Shutters! Let's not forget buying the pictures that they take onboard the ship and CC! Some great shots. For the most part the photographers will take pics with your camera, too, but they always seem to be better at using their camera than mine (and mine's just a simple point & shoot). Hmmm....fishy! Anywhoo, if you don't want to be tempted, don't even look at your Shutters pics. If you're like me, best to set that budget before hand and force yourself to stick as close to that budget as possible.
Parking. I think you said you were doing a 3-night, right? 3-night parking at the port is $60. I think the Country Inn & Suites does the park-n-cruise thing. There are other off-site parking places if you don't want to stay out by the port the night before. Both times we've cruised we've parked in the structure at the port near the walk-across bridge thing into the terminal. Extremely convenient...one we pay thru the nose for. It's up to you, tho. There are options if the onsite parking is a pill you can't swallow. I understand.
So to recap:
-Gratuities
-Porter/Room Service tipping singles
-Drinky-drinks (optional)
-Excursions (optional)
-Souvenirs (optional)
-Specialty dining (optional)
-Spa services (optional)
-Shutters pics (optional
-Parking (optional)
-Deposit for your next cruise (I'd love to call this optional but, for some reason, it's not quite optional for me...LOL)
Thank goodness "Fun" is included, right?! LOL!
Have a fab time!