1. Different techniques used in photography.

2. The purpose of photography is to take a photograph interesting enough that other people want to see it. Physically taking a picture is fairly easy. First, you point the camera at the image you are trying to capture. Next, you look through the viewfinder of the camera to get the desired framing. After that, you have to either manually or automatically focus the camera depending on what type of camera it is. Also, you have to adjust to the correct lighting either manually or automatically. After all of that, you press down the shutter button. The hard part of taking pictures is the composition.
Usually, good pictures are the result of paying careful attention to some basic elements of composition together with appropriate lighting and an interesting subject. There is no correct way to take a picture. Four different photographers photographing the same scene could create photographs each having an entirely different composition, yet being equally interesting.
Here are a few things to consider when taking a photograph:

3. Simplicity
Be sure that only the things you want the viewer to see appear in the picture. Your message will be lost if there are too many objects cluttering up the background. Consider using depth of field control to keep the background out of focus if you can't find an angle or framing to isolate your subject.

5. Contrast
A dark subject will have more impact if placed against a light background and vice versa. Although, contrasting colors can be used for emphasis they can become distracting if not used correctly.

7. View Point
One way to change a picture drastically is simply by moving the camera up, down, or to one side. Coming up with an unusual point of view is how photographers take prize-winning photographs.

10. Frame
A "frame" in a photograph is something in the foreground that leads you into the picture or gives you a sense of where the viewer is at the time it was taken.

12. Balance
Usually, informal (asymmetric) balance is more pleasing in a photograph than formal (symmetric) balance. So, placing the main subject off-center and balancing the weight of it with other smaller or lower impact objects will be more pleasing than placing the subject in the center.

14. Rule of Thirds
The rule of thirds is a principle taught in photography which is based on the theory that the human eye travels naturally to a point about two-thirds up the page. Additionally, dividing a photograph into thirds allows you to achieve the informal balance mentioned earlier.

16. Diagonals and leading lines
Linear elements (roads, waterway, fences etc.) are usually viewed as more dynamic when they are placed diagonally as opposed to horizontally. In this example the river is moving diagonally.

18. Focus
Your subject is what you are photographing, how you use the focus and include the background or other elements may help the photo.

21. Silhouette

22. low key

23. high key