I think of all the techniques I've learned during my photographic journey, this one is one of my favorites. All you need to do is look for a brightly lit subject in front of a dark shadow, like this goose.Then just close in on your subject while keeping the background in the shadow.
It works great with plants too.
And flowers come out beautifully when photographed against a dark background.
So, go out and look for those dark shadows with something fun in front of it and you can get a black background too!