Come with your hair styled. Bring any products/tools you normally use every day for your hair in case they are needed.
Makeup for headshots should be light and natural that emphasizes your natural beauty. Excessive makeup will show up too much in a headshot. Avoid heavy base and too much eye makeup, especially eye liner. Don't go overboard filling in brows. For lips, some light gloss is good, but not heavy lipstick.
For the eyes, some mascara (don't overdo it!) and natural shade of eye shadow that matches your skin tone. We don't want anything distracting from your eyes! Bring anything you need to touch up your makeup during the session. Try to avoid makeup/lipstick that is really shiny.
For headshots, minimal jewelry is best so nothing distracts from your face. Studs or smaller earrings are generally best. I recommend no necklace, but if you choose to wear one, make sure it's subtle.
If you alternate between glasses and no glasses, I recommend not wearing glasses for the session. However, if you always wear glasses and it would be weird to get photos without them, wear them! Just be sure to clean them before the session, and also bring multiple pairs if you have them.
Please come with your hair styled. Do not get a hair cut within a couple days of your session. Bring any tools/products that you normally use for your hair every day.
Facial hair is fine in a headshot. I recommend going with whatever the culture of your organization is. If facial hair is cool, then go for it. If your boss prefers clean shaven, definitely go with that!
If you alternate between glasses and no glasses, I recommend not wearing glasses for the session. However, if you always wear glasses and it would be weird to get photos without them, wear them! Just be sure to clean them before the session, and also bring multiple pairs if you have them.
With all of that in mind, it's important to look like YOU in your headshot. If your normal style breaks these rules, then go for it!