I went on the Tapas and Togas in June this year and for soft drinks you can buy a soda card that comes with a drinks bottle. It costs £15.00 and you can get 20 drinks you just take it to the bar and get it refiled. You can buy this when you gor to the bar on board. Also water, tea and coffee is available in the sunweaver and the plantations restaurant all day free of charge and in the mornings there is apple juice and orange juice free in the restaurants up until around 10.30 when breakfast finishes.
Alcholic drinks are about the same price as in the uk and all you do is give the staff your cruise card and at the end of the holiday settle up on your bill like you would do in a hotel.
There is no option for an all inclusive drinks package on this holiday which I would have liked to have seen but you can buy bottles of water and soft drinks in port and take them on the ship with you. You can buy spirits from the shop on board although I think they have a small charge if you want to drink these in your room.