HOW SHOULD I PREPARE? 
Depending on the package, if multiple outfits are offered I would greatly encourage it! I’ve had clients wear everything from a dress, sweater and jeans, or even show clothes. I always recommend wearing whatever you are most comfortable in and what will be easy to handle a horse with. High heels and wedges are discouraged, especially if we will be walking around in dirt or grass. 
I always highly recommend having your hair and makeup done professionally if you are able to, but it’s not required. 
OUTFIT SUGGESTIONS?
I recommend having different options and types. The top three are casual (sweater, blouse, jeans, etc), a more formal look (dress), and riding/show clothes.
RECCOMENDATIONS:
Neutral tones and colors match with every horse! Can never go wrong with soft pastel colours as the are very pretty.
White or black tops can be worn, but require some form of detailing (eg: Lace), as they can be hard to photograph.
Bright, plain colours work well.
Jeans and a top or polo is always a safe option. 
Avoid busy patterns that might not photograph well. Also clothing is better without logos and/or words.
Don’t be afraid to layer! A cute jacket can be worn and taken off to create two different looks!
Accessorize! A simple necklace or rings can add to the overall look in a huge way.
Closed toed shoes are preferred to protect your toes!!
HOW SHOULD I PREPARE MY HORSE?
For the best images, the horse should be as clean as possible. I recommend them to be show-ring ready. The images will be taken primarily in a bridle, but if you have a nice leather halter and chain we can switch into for some shots it is also recommended. Simple metal snaffle bits are recommended for the best overall look. Bellow is a list of recommendations for getting the best image possible: 
RECOMMENDATIONS: 
- Entire body brushed and dirt free
- Completely dry
- Green spots removed
- Mane and forelock brushed straight
- Nose, mouth, and eyes wiped clean (bring a rag!)
- Hooves painted
- Bridle wiped down and clean
- Bit shiny and wiped
- Braided (looks stunning when possible!)
I also highly recommend that a second person be there (besides you/the handler)! I sometimes don't have assistants and having a second person to help crinkle wrappers and get their attention is highly advised to make the shoot go by smoother!