The challenge of landscape photography is that you do not have control over the placement of the elements in the scene, and as such, it can be challenging to create compelling compositions. If you are new to the genre or find yourself struggling a bit, check out this fantastic video tutorial that will show you some common composition mistakes and how to correct them or avoid them in the first place.
Coming to you from Mads Peter Iversen, this great video tutorial discusses some excellent tips for landscape photography compositions as well as some common mistakes to avoid. By far, the most common mistake I see is not including a foreground element in the frame. The problem is that we usually use wide angle lenses for landscape work, and without a foreground element, the resulting image can end up looking rather two-dimensional and flat with a large void in it. Adding a foreground element helps to bring dimensionality and depth back to the photo and can also help bring your viewer's eye into the photo. Check out the video above for the full rundown from Iversen.
And if you really want to dive into landscape photography, check out "Photographing The World 1: Landscape Photography and Post-Processing with Elia Locardi."