I use my iPhone SE quite often. The "secret" to iPhone photography is a simple one: use it like a "real camera"!
Move your camera position to improve the shot. Keep the camera steady. THINK about the composition. Work on timing. Decide if the best composition is square, or vertical, or horizontal-for every subject and for every shot! Use camera support, don't shoot one-handed or while walking. Download the images to your computer, and use Lightroom or some other image editing application to optimize the pictures.
MANY very fine images were made with very inferior "cameras" in the film era, and even in the modern digital era; today's iPhone is a pretty decent camera by historical standards. Use it like what it is: a "real camera".