Here are some tips that may help:
- What kind of images do you like to work with? Nature, graphics, people, animals?
- Search through photos you have already taken for something that you think will make a strong black and white image.
- Remember that you don’t have to use the whole photograph; crop it down to just the part you want to use.
- Learn a few basics about Photoshop or whichever photo editing program you choose to work with to convert your images from a photograph to a black and white image with high contrast and no gray.
- Learn to apply filters to your black and white photo to create different effects.
- When taking photos with screen images in mind, zoom in to your subject to eliminate as much background as possible.
- Another way to eliminate background is to angle your camera so that perhaps the sky, if you are outdoors, or a mostly solid color object, if indoors, is your background.
- If you are photographing natural elements such as plants that can be cut, you can stage your photo against a white or black background.
Here’s a photo of a zinnia and how it looks converted to black and white, with 5 different filters applied.
There are lots of options and once you start playing with images, it's hard to stop!