1. Keep the original nearby
Compare the edited photo with the source. Review the whole composition, then look more closely at the changed area.
2. Check nearby edges
Look at horizons, straight lines, faces, text and repeated patterns near the selection. Watch for unexpected smears, repeated texture or changed shapes.
3. Try another selection
If the background looks wrong, use undo and adjust the marked area. Try one object at a time rather than assuming a larger selection will give a better result.
4. Check the saved image
Review the saved photo before sharing it. Keep the edited version separate from the original, especially when the edit changes the context of the scene.