Shoot images with dominantly two main colors that are in contrast. the subject should be in one color and the background in the other color.
I created this image using a 50mm prime lens at f 2.8. The subject (leaf) is in brown and the green bush forms the background color.
Enjoy this exercise and Fall colors offers excellent opportunities to create very intriguing images.
PS: I am sure you have noticed that there is a secondary color contrast in this image. The bottom is black and the top is white.