There are more ways to create depth beyond just using lead-in lines and light. One can use height. Yes, when you are shooting down is just creates an open vista. It stretches the foreground and middle-ground thereby creating depth. Here is an example:

This vantage point did not have the greatest amount of height but it was enough. Height enables you to see far. But please, don't be satisfied with just height. Please still apply everything we have been talking about in this blog. In this case, the sand forms a road that leads into the image. The sand has ripple lines that add to the encouragement to look into the image. Be on the lookout for these things as they make a huge difference.

          I repeat the words of Ansel Adams which I posted once in another blog: "The difference between a good image and a great image is often just a few feet." (paraphrased) So walk around and find that which adds to the image. Look for subtle things to invite the viewer in. A few feet this way or a few feet that way can make a big positive difference. Lighten these paths just slightly in post to emphasize them.

          If you have a choice mostly decide to shoot down for deep landscape images. Get some height, elevation typically adds depth.