Exposure is entirely dictated by the light conditions when you are shooting. There are no perfect settings – you need to use your light meter to “read” the light level, then set ISO, Aperture and Shutter speed accordingly.
There are certain rules of thumb you can follow – generally landscape shots are sharp from front to back, so we use small apertures to achieve this.
This simple info-graphic is a quick guide – it’s by no means conclusive and there are many exceptions so please read it as a quick reference.