Adjust the camera focus before capturing. Set the focus on a spot with even or slightly softer lighting. Do not focus on a spot that has strong light or reflective materials.

Make sure your lens is clean.

Make sure your lens is placed correctly on the lens of your smartphone.

Make sure you've got a green circle while capturing. If you see a yellow or red circle, it's recommended to try again.

Adjust the phone and tripod to make sure they are 100% vertical.