Photographic models usually work for advertising agencies, mail-order catalogues or fashion magazines, etc. Their work is carried out either in a studio or on location. Some modelling work is quite specialised: when, for example, a model with a particularly good feature such as nice hands, teeth, hair or eyes, they will be able to model in advertisements for products manufactured for that feature. When working, the photographer will give the model instructions on how to move, what sort of expression to have or how to pose: sometimes the session will be conducted with a background of music to assist the model to move or pose without being self-conscious. Models spend much time caring for themselves and their looks, and also looking for new work, unless they are fortunate enough to be permanently employed, which is unusual.