The composition is one of the hardest aspects of landscape photography. There are many ways to compose a photo, and having a strong foreground is a common tool to create depth in your photos.
In this calm and relaxing video from award-winning landscape photographer Adam Gibbs, he explains how he approaches a scene with the intent of creating a strong depth in the photograph. He explains you cannot just use whatever object you come across, slap it in the lower third, and make a cohesive photo. It takes much more to create depth using foregrounds.
Through several examples, he emphasizes you have to have an eye on all the small things. Given you use a stone or a boulder in your foreground, it has to make sense for the entire photo to include it. If the boulder does not somehow relate to the midground and background, it is just a boulder. The boulder has to be there to drag the viewer into the scene. You can have the edges of the boulder line up with background elements; if it is elongated, you can have it point toward the background; or if there are several boulders, you can use a repeating pattern to lead the viewer into the background.
He also touches on lens selection and points out the problems with wide-angle lenses. Wide angle lenses have a tendency to dissociate the foreground from the background, as the background becomes very small. On the other hand, using longer focal lengths, you run into problems with depth of field. Knowing when to use what will highly benefit your landscape photography. Gibbs also touches on perspective and compressing your scene.
Gibbs has many videos on composition and light worth checking out. Check out the video above and let me hear your thoughts down in the comment section.