When is the best time to book a maternity session?
I usually suggest around 32 weeks. You may not want to book too early before you dont really shoe, but you also don't want to wait too long because babies have a schedule of their own and sometimes they decide to come a little early. As a twin mom of 29 week babies, I tend to lean on the side of getting them done a little sooner. However, if this is your second baby and your first was right around his/her due date, I don't mind waiting a little longer.
Is hair and makeup provided for maternity?
It is not but I do have some amazing makeup artist and stylists I recommend to my clients. Not everyone wants to get all dolled up, but sometimes that is EXACTLY what a pregnant mama needs!
Anything else I should do to prepare for my session?
My biggest recommendation is to treat yourself to a mani/pedi, preferably something neutral or that matches with the overall theme of the session. A sugar body scrub before you shower and some amazing lotion or body butter to really get your skin glowing even more. I'd suggest making sure you have eaten something before arriving and dont starve yourself. Not eating is a sure way to not feel your best for these images you won't get again, with this pregnancy.
Do I need to buy an expensive dress for my maternity session?
This is totally up to you! Some people want a specific feel for their maternity session and that is totally fine. I do have a client closet that I allow my moms to go through during the booking session to see if any of thos ebay work, before they go and spend a bunch of money on a dress.