Photo Skillage

Contrast-
This improves the photo by making it a little more defined. Soloing in only on the dark parts of the face/head such as:
Hair
Eyes

Lips

Nostrils
Chin Shadow (light)

I like to use a lot of contrast in my pictures because it makes the audience focus more on the dark/light contrast of a certain pictures features, often highlighting edges and curves.

Rule Of Thirds
A picture is too boring if your object is in the center of everything. It doesn't look right. In order to fix this, people use the rule of third, placing their main object/objects in seperate boxes. It is like a tick tack toe board. Never center your object in the middle, always have it off in another box. This will make your picture and the objects in your picture, more even with the background, giving it room.

Backlight

Backlight improves alot in a photo. If a picture or shot is too dark, add a backlight to highlight such things such as outlines, curves, objects etc. Using a backlight can add a cool almost edited or photoshopped look to you picture.