A few years ago my 5DS dressed as Prince Eric. He wore jeans, white shirt and a red sash. He also wore boot shoe covers froma pirate costume but you don't need them for the effect. Ariel LOVED him! She kissed him on the cheek which stayed for about 2 days (what's in their lipstick?). He still talks about it 2 years later.
He also wore a Peter pan costume and got lots of attention from tinker bell and Peter pan.
He is already plotting what he wants to dress as for our next trip!
Boys in costume get much more attention for the characters then the girls since it is a rarer thing. My DSL defiantly stole the show at the princess dinner dressed as prince Eric and it was so easy. I think my daughter dressed in a beautiful Belle costume was jealous.