A lot of people may think that the subject is the most important part of any given picture. While it's true that the subject is the focal point of the picture and may even be the reason the picture was taken, for a truly masterful picture it's all about the light. What is the source of the light? What is it illuminating? How bright is it? How does it color the subject?
Bright light can be very harsh on the subject.
Same subject (our lovely daughter), same beach backdrop but this time as the sun is setting. Notice the difference in the skin tones. See how her eyes stand out.
Here are some pretty colors, but this one is lacking something.
Illuminate it with a little light from behind. It makes a more powerful statement.
What you do with your light depends on what your goal is. Sometimes you want to show the leaf.
Sometimes you want to emphasize the hole in the leaf. That's the same leaf at the same time of day. One with the light behind me, the other with the light behind the leaf. In the first one you don't even notice the hole, but it's there.
How do we illuminate our stories? Do we use light at all? Do we shine harsh light on the subjects or let a gentle glowing reveal them to our readers? Do we show our characters in different lights and different angles to give a complete picture of who they are--flaws and all? How important is light to your story? Is it a symbol you use? For mine it is very important. It is a source of truth. It reveals hidden elements. It helps the MC see her path and follow it.
Just a few things to think about.