Flipping a picture on your iPhone is a good way to get a mirror image, such as if you need to read backwards text.
Photoshop offers a wealth of tools for cropping images. You can crop to an aspect ratio, use content-aware fill and many other techniques.
Your best odds start with a great prompt. Getting great results isn't about magic; it's about giving the AI a better description of what you want. Experts call it "prompt engineering" but you don't ...