​Noise, blur, and subject are three very real challenges photographers can face when trying to capture images at night. There are many ways to work around the obstacles and create interesting images both while taking the photo with your camera and during post-processing. Let me explain.
 
In order to photograph at night, you need to set the camera to much higher ISO levels, and that can generate noise. Various photo editing programs and filters can reduce that somewhat, but one way to solve the problem is to work with the noise to create a particular effect. The image below was shot at ISO 16000, a shutter speed of 400, and at aperture f/20. When processing the image, I edited the moon by separating it from the background and worked with sharpening and noise reduction/blur filters in Photoshop to get the effect I liked. I was not concerned with having an absolutely sharp image. 

Blur can be a real problem. Using a tripod may be fine for certain night shots, but it is not always practical. You need to set a very high ISO and sufficiently high shutter speed so that the exposure is adequate and that blur is minimized.
 
In this image from Lisbon, I was mostly interested in the streetcar and the hotel. This was ISO 1600 and a shutter speed at 100. The people walking show some blur, and the man with his arm outstretched has a blurred and unrecognizable face. The solution is to shoot at much higher ISOs and faster shutter speed and deal with the noise issue as with the moon shot above. Or make blur part of the overall effect.

Finally, finding a good subject for a night shot can be a challenge. You can often take your nighttime photo and improve it in post-processing and eliminate extraneous elements by cropping and focusing on the core subject matter of your image that has sufficient light.
 
In the photo below, I was most interested in the interaction between the grandfather and the granddaughter. Her face is not large and all the features are not shown in full detail, but there is enough sharpness to show her smile and line of sight. I dealt with the noise issues as discussed above, but felt this worked because what I wanted to show was sufficiently sharp, in focus, and discernible. This is also a situation where I used selective sharpening over parts of the image and did not crop too tightly. I didn’t care if some of the things were soft focus.

Night photography encompasses many subjects, and problems in one area may be solutions in another. A certain amount of noise, blur, or softness can add to the effect. The final product doesn’t have to be perfect. Know your camera and take advantage of one of the many editing programs to make your image even better.

Composition is basically how the elements of a picture interact with each other. Is there a focal point that gets our attention? What is the subject of the image? How does the composition make that subject stand out? One of the challenges in landscape photography is presenting a clear subject—not just a snapshot of a general scene.

The image seen above is Kugler Falls which are small waterfalls in Central New Jersey. The stream empties into the Delaware River, however, the volume and beauty of the falls depend upon recent rainfall. In other words, there may be no more than a trickle if the weather has been dry. The flow was perhaps at a quarter or a third of its strength on the day I took this photograph. A few separate streams of water were enough to show the falls but not enough to project it in any dramatic way. In order to present a more interesting composition, I expanded the frame to place the stream in the lichen-covered boulder field through which it passed. My subject matter now was not the falls itself but this more dramatic spot along the stream.

Note the logs protruding from the upper left and the lower right of the image. The eye is drawn from one to the other in a diagonal, something that expresses dynamism and motion. Other diagonals are in the leaning tree on the right and the ridge of the boulder that moves from the lower left towards the middle right edge.

I wanted to emphasize the setting and decided to include the trees which occupy the top third of the image. A close-cropped image of the waterfall and the boulders might have been interesting for texture, but the image has more of a sense of place because of the inclusion of the trees. The green of the trees also picks up the green of the lichen and helps integrate the image.

You get a general idea of the rugged, isolated nature of this spot even though it is less than half mile from a road.

So think about composition when the original and desired subject matter of your image (in this case, the waterfall) is not enough to sustain the image. Look around. Think in terms of a broader context. Maybe instead of the waterfall the subject matter can be dramatic boulders, the mature forest, and the fallen logs.