You can always find harmony in nature.
I am not sure whether there is a formula for it.
For my picture taken in Hokkaido, the formula appears to be:
Harmony = Trees with Autumn foliage + Waterfall + Stream + Mountains
Maybe, this is too simplified and deterministic.
Peach blossoms and plum blossoms are my favorite flowers.
I have travelled to other countries just for the sake of seeing them in their full bloom.
Here are two photos taken in Japan; one with a light background and the other with a dark background, but both are good examples of harmony.
The light one illustrates how this flower can be in harmony with the bamboo. It stands out but in harmony with the background.
The dark one shows how this flower can be in harmony with the flowing stream and the background.
Both photos were taken by my classmate YM Chan.