As a D+ You now will receive 5 'vouchers' a day, automatically loaded on your SeaPass at 5 am every morning. They do not carry over to the next day, but they are sharable. If I don't use my 5, I get drinks for others or for my room attendant 🙂 You can use them for any drink up to $14, any time. Possibly $13 on some ships it will be listed on your welcome letter. If ordering a Water or Soda and you don't want it counted as one of your 5, just let the bartender know.
I am not a big drinker but I do drink a lot of bottled water, specialty coffee, and fresh OJ so I have been getting the Refreshment Package (when it is at a reasonable price) and using the vouchers for my cocktails 🙂