Rule of thirds means focusing the main subject of the image on a third of the picture.
This draws all the attention to that third of the picture.
Symmetry
Reflecting an image, it does not need to be in water. Anything that shows the mirrored image of your subject.
On the left and right it is easy to see that there is a line of symmetry.
Angles And Perspective.
It is important,when taking pictures, to look at things from a different perspective. These new and different angles help to make your pictures look unique and different.
Leading Lines.
Make something the focus of the image by guiding the eye to it, this can make something seem more important or dominant in the picture.
Framing.
Bringing all the attention of the picture to one subject by highlighting it.
You can do this by framing the subject with different objects.
Focal Point.
The focus of the picture, it is where the eye is drawn.
Minimalist.
Simple pictures where not much is happening.
Maximalist.
The opposite.
Colour.
How saturated then colour is in a picture and how much of the colours there are. It also is related to the colour wheel, opposite colours stand out against each other.
Pattern.
In pictures that focus on pattern, there is not a lot of composition, just a pattern of an object.
Forced Perspective.
Forcing something to feel bigger or smaller than it is by angles and distance.