One of the most common mistakes beginning photographers make is taking a picture of the first thing they see and not going any further. Spending a little time to walk around the subject, explore it from different angles and distances, can often result in a better photo.
Most people "see" good pictures, but then don't know how to take what they see and turn that into an interesting photo. In this example, we've found some grasses at the edge of a marsh. Walking up, we see the nice stalks of grass with big heads hanging like flags and realize they would make a good picture. So, we shoot it. Now we've got a picture, but we've included too much. Anyone looking at it will see a background with trees and a highway that competes for their attention with the grass we really wanted to show. (Image 1)
So the first thing we need to do is decide what it is that caught our eye? What is it that made us want to take a picture in the first place? If in fact it's the grass, then why include all the other stuff? Why not move closer and shoot just the grass? If we get closer and fill our viewfinder with the grasses, then we can get rid of the other distracting elements in the scene. (Image 2)
We have some options when it comes to getting closer. We can either walk up to the subject, or use a longer lens, a telephoto, to bring the subject closer. Most people today are using cameras with zoom lenses, so by simply twisting the zoom ring (or pushing the zoom lever on a compact camera) we can change our angle of view by zooming in on the grasses, forcing the camera to ignore the rest of the scene.
Now that we've found a more interesting way of shooting the heads of grass, we can walk around them and see if we can find a better angle. Look at how the light strikes the grass, and pay attention to the background. Look for a background that's darker than the head of grass that will help it stand out better. (Image 3)
Remember, you're no longer paying for film. There's no reason not to shoot a lot of photos. Shoot, shoot, shoot, until you're absolutely, positively sure you've got the picture you want. See if there's a different way to shoot those grasses, maybe from down low to silhouette them against the sky. It's always easier to delete the photos you don't need than to go back and try to re-shoot the same scene. (Image 4)