Most jobs for studio art or design teaching positions require that you submit not only a visual portfolio of your own work, but also a portfolio of work by students you have taught. This gives search committees an idea of the effectiveness of your teaching.
Because of this, you should make it a habit to record all the work your students submit to each project review. Two options would be to bring a camera to all reviews and shoot the work then, or to collect the work and then shoot it under more controlled lighting conditions.
Remember that the better the quality of the reproduction, the greater the impact the image will have on the viewer. To that end, make sure that you are using a lower ISO, that the white balance setting is matched to your light source, that the artwork fills the frame, and that the artwork is square in the frame.
A bad image of a great artwork will not do it or you justice!
Once taken, organize the image files in your computer by assignment. This will make them easier to find when you need to. Also make sure to embed the student’s name and the medium into the image for future reference.