Smartphones can be pretty good when it comes to choosing settings, but not always. Metering can sometimes be pretty shoddy indoors and in cloudy conditions, which is where overriding some of the settings can come in handy. If you think the white balance is off, change it. If the photo is underexposed, use the sliders found in most camera applications to boost it. If youd prefer grain to blur, up the ISO used by the camera manually. Dont forget about the flash either, which is sometimes necessary.