Have a minimum of five complete outfits. There is absolutely no shame in coming with as much as 15 outfits. The complaints from headshot photographers are always when people bring too little as far as options.
A lot of actors are broke and have limited clothing. Some people borrow clothes and some people will buy clothing just for their shoot and return them directly after. That is up to you and your moral compass. But be sure to communicate that you plan on returning clothes to your photographer so they don’t rip off a tag during the shoot or throw away that little sticker that says the size. But take note, as you audition you will need to make sure you have audition clothes and start thinking with that when you go shopping.
Headshots are not showing the lower part of your body, so focus on the top and make sure you wear something you are comfortable squatting in that makes you feel good. I do not recommend totally slumming your lower half. You might have a shot that you use that has a little leg or something in it. So no sweats. But a comfy stylish pair of jeans or slacks. Some agents will ask you to supply full body shots, but not often. Full body shots are used mainly for ZED cards. ZED cards are a promo pieces with multiple images or a digital book for models that show the range a model needs. Most agents don’t ask for full body unless they also have a modeling department. So focus on the waist up. Do not waist time on our headshots with full body otherwise. If you need full body shots get those in a social media shoot.
Shoes are up to you. Unless you are doing full body shots because your agent requested them your shoes often won’t show. But shoes can make you feel a certain way. I have women that will wear certain heels because they feel boss wearing them. These little things help you. They might not show up in the actual shot, but if it makes you feel boss, bring them and use them.
I should not have to say this, but since it has happened before, don’t come to a photoshoot high. There are a few people that will do that because of nerves and they think it will help to smoke out or to take a pill. But these shots are you communicating to the camera with a photographer. If you are high in any way you are cutting off your ability to clearly communicate. That does you zero favors.
Bring make-up with you. Photoshoots should start with natural clean make-up and can be built up as you go. Most women will pay the extra money for a make-up artist. This can make your shoot twice as expensive and it is up to you to decide if you need or want it. A good makeup artist is worth it. But I have had hit and miss with make-up artists for headshots sessions. Most women know how to do the range of make-up required for headshots and if you are trying to save money go for it unless you think it will divide your attention and energy. My daughter prefers makeup artists because she can have a sense of calm between looks and refocus herself. It's less stressful. However, that may be a luxury you can't can't afford.
Men often don’t think about makeup, but there is one thing ALL men should have in their pockets and use before any photoshoot or any audition (more than half of your in room auditions will be recorded by casting). All men need cherry Chapstick. I am being brand specific here. Cherry Chapstick has a slight color to it and does not have a glossy shine. This prevents the lips from looking ashy on camera. It gives just enough color without making it look like you are wearing lipstick or gloss. I do recommend that men also bring a translucent powder with them or shine blotting cloths.
Have a hit list of the looks you want to accomplish. I have even had clients come with look books as well as their casting list. This is great because you can organize the shoot. You can look at what you need and when to change hair and make up. Make sure you cover the looks you are going for with lighter makeup before you add the heavier makeup.
I also suggest bringing safety pins and women bring hair pins and hair clips. Especially if you aren't hiring a hair stylist.