Clean your lens
I always tell people to clean their lens first—no, I don't mean cleaning it with your finger because your fingers are always greasy. Simply take a piece of your shirt and clean the front elements of your smartphone lens. The left-side image of the ducky shows lighter darks than the image on the right.
Locking exposure and focus
Controlling light becomes much easier with this type of functionality, where you can tap and hold to lock your focus and exposure in place. This allows you to scroll up and down to control the amount of exposure you would like. This gives you back some control to your images, and is especially great in high contrast situations. Autofocus, on the other hand, has the tendency to create images that are too light or too dark.