Where you place the foreground in a landscape photo has a big impact on how the photo is perceived. Placing the horizon high in the frame (as I did here in this shot of Stonington, Maine) increases the sense of space in the foreground. Conversely placing the horizon low accents the sky. Probably the worst placement is right through the middle because that cuts a scene in half and divides the viewer's attention. Just ask yourself which part of the scene you want to dominate the frame. If you want more emphasis on the foreground, place the horizon high. If you want to show off the sky (in a sunset, perhaps) lower the horizon. Try it, it works.