Landscape photography is a wonderfully accessible form of photography. All you need is a camera, a lens and a tripod (and even the tripod is optional at times).
So, what are some of the common mistakes to avoid when you are starting out?
Establishing depth
Landscape photography is about building depth. Without depth, your images will look flat and two dimensional. You want a foreground, middle ground and background in every image. Build up your skill identifying these layers in a scene. If you do, you will have mastered one of the most important skills.

This image demonstrates the application of depth. There is a foreground, a mid ground and a background, all three of which serve to lead the viewer through the image.
Eye level is boring
If you only shoot at eye level, or tripod level, your images will start to feel boring after a while. You will also miss the opportunity to depth into a scene. So, start at ground level and build your way up to eye level. Today’s cameras mostly come equipped with tilt screens, making ground level photography much easier than it was back in the days of fixed screens. On top of this, most high quality tripods come with features that allow for low angle shooting.

In this image, a low angle creates interest in the foreground, all while the distant peak of Mount Cook looms through the mist in the background.
It's more than just wide angles
Landscape photography is not just about wide angles and big scenes. Field of view and aspect ratios are important. These can help focus attention and remove distractions. So experiment and see what you can get. My standard kit includes a wide angle lens in the range of 16-35mm and a telephoto lens in the range 100-500mm

By zooming in, this image strips away all distractions, focusing the viewers attention on the distant mountain peaks and the clouds.
Don't rely on Photoshop to fix your images
This is one of the most common mistakes. Overprocessing your image in Photoshop, Lightroom or any other editing suite to make up for a lack of colour, depth and visual strength in a landscape. My advice is to use post processing to make a good image a great image. Subtlety in your final edit is the key. You want your scene to look as natural as possible.

I like to keep my images simple and true to what I see. With the right lighting and composition, you don't need a great deal of post production editing.
Golden hour is not the only hour
There is no disputing that the golden hour produces striking landscape imagery. But the truth is that great landscape pictures can be captured at any time of the day. It is all about making the light work for you. So, explore different lighting, even during the middle of the day.

Once the light is gone, a whole other world awaits.
Every photographer has been guilty at one time or another of the above mistakes. The most important thing to remember is that these are relatively simple lessons to remember and overcome. In doing so, you will find immense reward.
Cheers,
Russell