Contrast is one of the many parameters you can adjust in an image, and it's among some of the most important of all. This excellent video will show you five different ways to work with contrast to improve your images.
Coming to you from Mark Denney, this great video will show you different types of contrast and the many ways you can manipulate it to change and improve your images. You might think of contrast as a global property, but it actually works on many levels of an image to achieve different effects. For example, you can think of sharpness as the contrast between edges. The precision with which you can control it goes well beyond the basic contrast slider, and it's well worth taking the time to learn the various ways to fine-tune it. As with many adjustments, though, it is very easy to accidentally go a bit overboard with things, so be sure to step away from your image for a few minutes when you're done editing and return to it with a fresh set of eyes before the final export. Check out the video above for all of Denney's tips.
And if you really want to dive into landscape photography, check out "Photographing the World 1: Landscape Photography and Post-Processing!"