I've always thought that although you can shoot anything in monochrome, not everything works well in monochrome, although I'd caveat that by saying, it depends on how you shoot it, and how you process it. Maybe its because I've got some wet darkroom experience, but if converting to black and white digitally, I always make contrast and selective tonal adjustments.
I had some advice which was to start shooting textures, shapes and explore the interplay of light and shadow, etc, which is a good start.