Light and Shadow in Black and White
Lighting and shadows in black and white photography are probably the most important details that will make a great photo. They both work together to create contrasty images which is what most expertly taken black and white photos have.
The positioning of the sun (or lights if inside) is probably the most important of the two, because this will either create shadows in the image or not. Placing the subject directly in front of the sun, especially when its low in the sky will have the greatest effect, creating long dark shadows which will also serve as lead in lines in the image.
The alternative to this is photographing the subject with the sun directly behind you, and this will create a fully lit subject but may also create an uninteresting photo. Generally you don’t want the light source in front of the subject, (front lighting), because your photos will have less texture than they would with back or side lighting.
Fill in Flash
Using on camera flash can be useful if photographing with the sun directly behind the subject. This will avoid the foreground underexposing, since taking photos with the sun in the frame will likely lead to the darker areas appearing too dark. This may remove some of the contrasty shadows so should be used only if the aim is to remove some of the shadows.