The main goal of a loud and sexy hen party is getting as much attention as possible. This can be easily done if the participants of the hen party (that theme can be easily applied to stag party as well) are dressed as popular toys.
Most popular feminine toys are undoubtedly Barbie doll. She can be accompanied with Bratz dolls or any other new trends of dolls. Why they will get so much attention? Because daddies usually buy their girls many dolls and know them already. Of course, moms may express some controversial attitude to such party theme, but your goal will be achieved anyway – you will get enough attention from young ladies, moms and dads.
Another popular doll is oriental one – Hello Kitty. The dress can be really cheap as second hand clothes shops are full of Japanese style t-shirts for teenagers. Some pink skirts, cat make-up and some hello kitty bags. Japanese culture is really popular among the teens, but it will also attract the attention of adults.
If you are absolutely crazy and ready for a shocking experience, then consider dressing up like characters of most popular baby TV series In the night garden, Teletubbies or Tweenies. Upsy Daisy, Igglepiggle, Po, Laa-Laa, Jake, Fizz, and others will definitely attract the attention of kids, meanwhile their parents will need long explanations why these semi naked ladies are pretending as characters of favorite kids series.
Of course you can dress as transformers and get all the boys of all ages attention 🙂
The girl toys theme is little expensive as costumes are big and quite unpopular. However you can always rely on doll make-up and some pink shiny clothes from a second hand or even your grandma’s closet.
Hen party ideas 
Pink Skirts are always grab lot of attention! Fantastic for a Hen Party! 🙂