Composition

Draw Attention to the Subject 

http://fliptroniks.com/best-iphone-photography-apps-fliptroniks-com/
This photo is a good example of drawing attention to the subject because they blurred out the background behind the bike. They also used the neon color of the bike to their advantage.


Always Keep the Eyes Above the Center of the Photo

http://ginva.com/2012/03/99-beautiful-female-portrait-photography-examples-that-will-inspire-you/
This one has to do with the rule of thirds. Keeping the eyes above the center wont draw the viewer straight to the eyes and they'll actually look around the photo.

Brightest Part of the Photo

http://www.picturecorrect.com/tips/common-mistakes-in-wildlife-and-nature-photography/
The eyes will go to the brightest part of the photo first. Anything other than the subject of the photo being the brightest part of the photo will distract the viewer.
The Rule of Thirds

http://takeandtalkpics.com/fundamental-fridays-rule-of-thirds/
The viewers eyes are drawn to the center of the photo first and if they see that it isn't the busiest part of the photo or that it has nothing then they'll be forced to look at the whole photo. Putting your subject on one of the lines is the best thing to do while taking a photo.

The Rule of Odds

http://www.photokonnexion.com/the-rule-of-odds-uneven-composition/
The human eye feels better about a photo when it does not have an even number of subjects. The human eye is drawn to the center of the group and if there's nothing there then they'll just be staring at an empty space.

Patterns

http://scsurfbutler.com/2013/05/12/weekly-photo-challenge-pattern/
Patterns tend to be visually compelling because of harmony and rhythm. Pattern is even more compelling when you break the rhythm and then you continue the rhythm after.

Leaving Space

http://digital-photography-school.com/leaving-space-behind-moving-subjects-composition/
This rule has two ideas to it, breathing room and implied space. If your subject seems to be looking off into the distance then putting so empty space for it to look into. It makes the picture more comfortable.

Simplification

http://blog.wisdomtap.com/2010/05/rules-of-thumb-for-composition-of.html
To simply a photo is to get rid of distracting elements of the photo. Any distracting elements in the photo will cause the viewer to look away from the subject.

Symmetry 

https://sites.google.com/site/photographycompositionrules/rule-of-thirds/symmetry-and-patterns
Symmetrical designs are a great excuse to break the rule of thirds, because you want one side of the photo to look the exact same as the opposite side. Look for symmetrical images with strong lines, curves and patterns.
Viewpoint 

http://www.resimsi.com/cool-road-photography-background-wide-20548.html
Different viewpoints change the mood of the photo drastically, depending on which level you shot it you'll look like you're looking through something or someone's else's eyes.  Perspective can also change the viewer's perception of the size, so a different viewpoint can make your subject look larger or smaller, which could lead to a better photo.