SIMPLE ~ black and white photography loves minimalism, look for simple subjects to shoot. The less distractions the better you can focus on the image.
CONTRAST ~ look for strong contrast between light and dark. dark shadows and strong sunlight make for great contrasts in black and white images.
ANGLES ~ to make black and white images have depth look for angles. rather than taking an image straight on, look for the angel that gives the best shape to your image.
PERSPECTIVE ~ if you are shooting in a place where there is lots of motion, people, colour or distractions, change your perspective. move your position so that you get a simplified view of the subject you are trying to capture.
LEADING LINES ~ another way to draw your viewer into the image and show them depth is to look for the leading lines of the subject. what lines such as the edge of buildings draw you into the image.
SYMMETRY ~ look for symmetry to give interest in the place of colour. architecture often has symmetrical parts such as windows, vents, rails etc.
don't just turn your camera to black and white mode or edit after the shot, think about your image as black and white before you click the shutter button.