Seeing in black and white is all about seeing things in terms of shapes, both in terms of a three dimensional form, such as a person’s figure, and in terms of a two dimensional field, the graphical composition of the photograph itself.

For seeing the form, you’re working with light and shadow with the goal of representing your subject in terms of volume, highlights, shading, and so on. Like drawing with a thick slab of charcoal, it may help to think about things in broad strokes without worrying too much about the details. One technique I use is to half-close my eyes so I am mostly looking through my eyelashes in order to blur my vision so that I am not distracted by the sharp details and textures of what I’m looking at— just the light and shadow sculpting the shape. Let the light or shadow carve out the shape of the subject of the photo.

For seeing the field, you must learn to re-frame how you are perceiving the subject, and regard the real life scene before you as a flat photograph. This is all about seeing shapes, thinking about how the eye will travel across an image (generally starting at bright areas and faces, following lines and curves, etc).

An excellent book on seeing composition is Michael Freeman’s The Photographer’s Eye. Here’s an amazon link. I highly recommend this book to anyone starting out in photography, it is well worth the cost.