If she'll wear certain things: miniskirt, bikini, etc?

Simple as that.
Ask in the medium that she prefers to use, whether it is through email, text, or the phone.
Email is probably best imo.

She'll most likely say yes or that it depends on the outfit.
Your request is reasonable, and I'm sure all providers have a few miniskirts and bikinis.

From experience, the more time you give the provider, the better.

clothing request. It is best to make the request from a pic you have seen on her website. If it is a request that you may have seen elsewhere, you may want to inquire as to the proper size and then make the purchase at your favorite store. Almost all ladies will wear a new outfit you bought just for them.

In the past when I have been on a dinner date, I have taken my lady to a VS store and let her pick out and outfit to wear once we got back to the play pad. Ladies are appreciative of such thoughtfulness.

Thank you.

once the appointment is set..the good ones will ask you so dont have to..