Camera comparisons between flagships measure differences most people would not notice. Technique produces larger differences than hardware, and costs nothing.
Light is everything
The single largest factor. Position your subject so light falls on them rather than behind them, which is what produces the silhouette everyone accidentally takes.
Soft indirect light – an overcast day, open shade, near a window – flatters people. Direct midday sun does not.
Get closer
Most phone photos are taken too far away, leaving the subject small and the frame full of nothing. Moving closer beats zooming, because optical distance preserves detail that digital zoom destroys.
Use the zoom lens rather than digital zoom
If your phone has a telephoto camera, tapping the 2x or 5x button uses it. Pinching to an intermediate value frequently crops from the main sensor instead, which is worse.
Clean the lens
It lives in a pocket. A smeared lens produces hazy images and washed-out contrast, and it is the most common cause of disappointing photos.
Lock exposure and focus
Tap and hold on your subject. That fixes both, preventing the camera from changing its mind as you recompose.
Then drag up or down to adjust brightness before shooting, which is faster and better than fixing it afterwards.
Shoot in the higher quality format
If your phone offers RAW or ProRAW, it retains far more information for editing. Files are larger and worth it for photos you care about.
The habit that helps most
Take several. Storage is cheap and the difference between an acceptable photo and a good one is frequently which of five you kept.