This is one of the first rules of composition in photography.
Don’t center your subject in your photos. Instead, break your image into thirds both horizontally and vertically (Visualize a grid of three vertical lines and three horizontal ones.) Placing the focal point of your photo along the intersections of those lines will give your photograph more visual interest.

Think about what your focal point is and then remember to visually ‘place it on the grid’. Experiment and see what a difference it will make in your photos.