The thing about landscape photography is you can have the perfect scenery, everything framed beautifully, and your settings spot on, but if Mother Nature decides to give you the wrong light, the shot won't be there. This great video talks about what good light is and how to recognize it.
Coming to you from Adam Gibbs, this video talks about the types of light he prefers for landscape shots. After a long career shooting for gardening magazines, Gibbs notes he really appreciates overcast skies and the soft, diffuse light they provide. I generally agree with him. Maybe I'm just used to overcast skies, but I find that starting with a flatter light makes it far, far easier to shape an image to taste in post and tends to give me a lot more latitude to do so. As he notes, however, punchier light is often welcome too, particularly when you're focusing less on the details and instead including wider detail of a scene. It can be especially helpful when you use its contrast and variations in color to segment an image and draw attention to your subject while still including a prominent background. Give the video above a watch for more.