Alberto submitted this image of a sunset on a beach in Mauritius:

My comments:

• The mood here is wonderful; very serene and I think the shot does a good job of capturing the moment. I like how you’ve left enough room “in front” of the horse to the left. When you have a strong directional line, such as a living creature in motion, it’s essential to leave room for the viewer’s eye to travel that direction without leaving the frame.
• Overall, the capture is a bit underexposed. This is common for a shot containing the sun – your camera will want to reduce the exposure to compensate for the bright light source. Consequently, other objects are silhouetted. Though I love the silhouette effect of the horses and riders, the overall image could be brightened up a bit, to reveal more detail in the clouds and water, and to show more rim light around the edges of the silhouettes.
• Finally, the horse at the left appears to be a bit close to the bottom edge of the frame. A stronger composition would include more “weight” at the bottom of the frame to create more of an “anchored” feel.

Here are some quick revisions I made using the provided image file:

A few final comments about the edited version:

• Always keep in mind that when you have two subjects of similar strength, the eye has a tendency to bounce back and forth between them, like a game of ping pong. Note how in this photo, that tends to emphasize the empy area of water in between the two riders. This creates tension that is less than ideal. The composition would have been stronger with the horses positioned a bit closer together, and maybe a little more room behind the horse on the right.
• I lightened the exposure using curves. Unfortunately, this brought out a lot of noise from the provided JPG file. This underscores the fact that you really must always try to get the exposures correct in the camera, and especially, whenever possible, don’t underexpose. It’s often harder to clean up an underexposed image than it is to adjust an overexposed one.
• In Photoshop, I used the Canvas Size command to quickly increase the bottom portion of the frame, using a solid fill color. This would have been improved with some cloning to replicate a more realistic texture and tonal range; but ideally, is the kind of decision that should be made at the time of capture.

Thanks to Alberto for submitting this photo!