Incorporate things like roads, streams, shorelines, railway lines, or even railings, into your images. These are referred to as lead lines and are a great way to capture the way that a viewer is going to look at your photo. They will lead your viewer's eyes through the scenes of your photos.
Play with the shutter speed on your camera to catch unique and wonderful photos. If you have the right shutter speed, you can get beautiful photos that would normally happen so fast that the human eye couldn't process it fully. Try experimenting with shutter speed and a tripod at a stream or waterfall for some great photos.
Understanding color and using a color palette approach to composition can give more power to your photos, particularly when you want to use accent colors.