Speaking as a professional. :wink: . . .
I would say it depends on where you take your idea of an usherette from. Is it an idea of a scantily clad speakeasy cigarette girl? or a traditional cinema usherette? or somewhere in between? I would say that I consider an usherette to wear a *uniform* rather than a costume or outfit. Also, I disapprove strongly of all these girls showing off more wares than are for sale on their tray!
Recently my every-day use uniform has been much in the vein of the 1930's, a red suit with matching pill box hat. It's smart and hard wearing, and keeps me looking respectable for the customers. My chosen coiffure has been a neat black bob, very in vogue, and my specs as I am blind without them. For special occasions I have a grand scarlet blazer with brass buttons of which I am very proud.
In previous establishments (with a nod to the 1960's) I've been known to wear a pale pink nylon twin set, with my (at the time) trademark blonde beehive, and my very severe white chunky specs (I really was blind as a bat without them). But recently for the Candy Box Burlesque I was delighted to provide an exciting electric blue ensemble with matching pill box, and some nice horn rimmeds. The styling met with approval from staff, management and patrons alike !
So it depends I think on the setting and establishment in which your usherette staff shall be working.
As for where to source, I would be inclined to avoid commercial sites where they will churn out in large numbers a shoddy pvc frock or such like. Your staff may end up looking cheap, and possibly uncomfortable if the fit is not good. Still, if you have five staff to fit out, in identical uniforms, that may be an easy option.
If you wished custom made outfits, I would recommend Timeslip as already suggested - I know of their work (mostly bespoke) to be of exquisite design and very good quality. I have heard also that they offer very good value for your £SD.
Sincerely,
Deirdre