A big part of learning to take great photos is learning to see the world the way your camera sees the world. Once you learn to see like your camera sees, taking great photos will be much easier.
1. The Camera Has No Depth Perception
Your camera sees through one lens. This means that it has no natural depth to what it sees. The only depth perception your camera sees is an illusion based on the size of objects in its field of view. Humans see through two lenses, this means we have two slightly different images combined within our minds. This allows us to perceive depth and easily ignore objects we are not directly focused on. To see the world as our cameras see it, you need to artificially remove your depth perception. There are two ways to easily do this. The first is to shut one eye. This is easy to remember when looking through a viewfinder. The second is to squint. When looking at a scene without your camera, try squinting to help flatten the scene a bit.
2. The Camera Can't Distinguish Shades Very Well
Compared to the human eye, your camera can not see nearly as many shades of light. This means that often what we see as grey is recorded as white or black. We refer to this as the dynamic range. High dynamic range (HDR) photography uses multiple images to try and capture all the shades of light in a scene. To try and see the shades of light the way your camera does, look at a scene quickly without giving your eyes time to adjust completely. For example, if you are photographing a brightly lit scene - look at something in shadow for a few minutes and then quickly look back at the bright scene. For a brief moment you'll see overly bright (overexposed) areas in the scene before your eyes adjust.
3. The Camera Lens Doesn't Move
When we look at a scene our eyes naturally move around to capture different parts of a scene for our minds to put back together to form a whole image. A camera does not have this luxury. A camera looks straight ahead and sees everything at once. Replicating this effect takes a lot of practice when you are trying to see the way your camera sees. When practicing viewing a scene this way, it often helps to place your hands on either side of your eyes like blinders at first. This will help remind you to keep your eyes still and looking straight ahead as you check the scene before photographing it.