Sometimes I want to create a photograph that makes you look a bit closer. By letting the hair obscure the face in a portrait, most people will tend to look at the photo just a bit longer.
The hidden portions of the face make you look longer as your mind works to create an image of what the entire face might look like. To be effective you need to be able to clearly see at least one eye. The second eye is not needed at all.
This technique is very effective in a number of styles of photography. It works great in boudoir photography. Especially in bedroom sets, where the messed up hair in the face can take the mind down a fantasy. For maternity it can add a feeling of being a bit shy or possibly lost in thought about her new child, unaware of the photo. It is a fun addition to senior portraits where it can be used to portray a bit of mystery.
The one place that is does not work of course is headshots. A casting director needs to see a face.
Getting the hair in the face to look right can be a challenge. What I will often do is have the client lean down a bit and bring their hair forward. Then have them look up and give a gentle shake to let the hair start to fall back off the face. Typically we will have to do this a few times to get the hair to look right. I find this works better than placing the hair, as placing it seems to lose the natural flow of the hair.
Give it try next time you are shooting and see what magic you can create.