Many of the images from other photographers that impress me the most are those with simple compositions. I’m not saying that complex images can’t be successful. I just mean that, often, you can communicate more by showing less in your images.
“Keeping it simple” can be achieved in a number of different ways. If you shoot people in a studio, you have the option of choosing a plain background to concentrate attention on your subject.
You can simplify by using light that isolates your subject.
You can choose an angle of view that will simplify the shot. See these two shots below.
You can shoot high key with soft light against a bright background.
You can shoot low key against a dark background.
You can move in close to fill the frame.
Silhouettes can be really effective.
Shadow shots.
I love shooting against the sky because it simplifies my shot.
Frames can be used to simplify images.
Even in the very busy environment of a city simple compositions can be found.
Look for beauty in the simple isolation of the elements in your photographs.
You will be surprised.