C.Ann
We normally leave 10% tip for the buffets where the servers ONLY have to bring us drinks, and clear our plates.... If we really make them run (after a long day in the park, and our glass empties as fast as they can bring us a new one)we do leave more. For the buffets where they bring you the food, and it is family style we normally leave the full 20%. 15% is normally the reccomended, but the servers in WDW are normally Awsome. We have left more than 20% once or twice, and the server totally deserved it (I think we left between 25 and 30% for one of the greatest servers at Ohanas, she was AMAZING). This is just how we do the tips.