This illustration is from the Famous Artist's Course. It's really meant to be an example of how to add variety to your paintings with different textures and how to paint textures accurately. That's not my reason for posting it - while textures can be used to add variety to a story sketch, it rarely has much to do with putting over the story, which is all we really care about in a good story sketch. Unless the texture has something to do with a story point (like Donald Duck admiring the new leather seats in his convertible, I suppose) we rarely have time to put much polish on a storyboard and do things like spend time drawing complicated textures.
Anyway, my real reason for posting it is that it does a lot of things well that can be used to create depth in a drawing, which CAN be useful for story sketch!
One of the easiest, most effective ways to create depth is by have an object in the foreground (like the cactus) and see smaller ones in the background, further away from frame. The eye automatically assumes that they are all the same size, since they look the same, and assumes that the smaller ones are far away while the bigger ones are closer. Also note that the close ones have a lot of texture, while the far away ones do not. Since we see more contrast and more detail up close, draw a lot of contrast and detail on objects in the foreground. Have less contrast and detail on stuff that is far away because atmospheric perspective makes it seem that way - the haze that occurs outside comes between you and what you see. The further away stuff is, the more dirt and dust and/or water molecules in the air come between your eye and the object, fuzzing it out.
Another way to make it look like there is a lot of area in a story sketch and the field is really deep is to put alternating areas of shadow and light on the ground. See how there are areas of shadow from the clouds and areas of light where the sun is hitting the ground. And the areas of shadow get thinner and thinner as they go towards the horizon, of course, suggesting that the earth is curving away from us. The shadows falling on the mountains to the right also work really well to "wrap" over the mountains and help make them look three-dimensional, keeping them from becoming confusing graphic shapes.
Also the S-curve of the train tracks is really helpful in a lot of ways. It goes behind the foreground cacti and behind the mountain which always helps - overlapping objects on top of each other creates depth. Think about if the train tracks were a straight line from the bottome to the top of the frame - it would cut the frame in half, ruining the composition and also sliding your eye right off the page. And a straight line doesn't describe much depth - you don't see many straight lines in nature. The S-curve in a composition always works well because it takes up a lot of the picture space which ensures that there won't be any empty or dead parts of the frame. And even the top of the frame, where there isn't much to look at, is made more interesting by having the focal point of the train tracks. And I like how the train tracks describe a curve, while the mountains on the left are square and blocky, while the mountains on the right are traingular. The variety of shapes in the picture makes for real visual interest.
And this has nothing to do with the whole depth idea, but you gotta admire the way the two prongs of the cactus in the foreground really frame the train, and the way the little irregular squiggle of the smoke from the smokestack attracts your eye to the train (which is the center of interest, of course) by virtue of being a small, irregular but intense shape. And the three areas of greatest contrast are right in that spot as well - the black train engine on the light desert floor and the dark black right side of the cactus in the foreground, as well as that white spider-shape highlight on the cactus right there. And all the lines in the Composition point to the train - the top of the flat mountains, the lines on the slanted mountains, the curve of the traintracks....
Okay, I could go on forever but I'll stop now. You already know all this stuff, I'm sure, but it goes to the theme I've mentioned before: it's all simple stuff you already know, just applied in ever-more sophisticated ways, and making it look natural, which is a trick in and of itself!
Feel free to leave a comment here and let us know what else you see.