Well, what do you think of the first episode of season 4 of Downton Abbey? I think they set the stage for lots of shenanigans in future episodes!
Lady Lily, the niece that Lord and Lady Grantham are supervising certainly has the heart of a flapper. And her dress for the local dance outing reminds me of this dress described in the home sewing tips from Ruth Wyeth Spears. Ruth assembles squares of chiffon and attaches them to a foundation slip to create bias drape and an elegant "scarf" style frock.
I think this could be described as an "easy to assemble" frock. :) How would you like to dance the One-Step in this?