This picture is one that I used in my project:

These photos represent symmetry in nature.  Some were chosen, as opposed to others, for their composition.  For example if you look at the bright pink flower to the left you will notice that it is very similar to the flower below.  But the flower below's composition is poor.  The flower doesn't fit entirely in the photo and it wasn't taken straight on.  My own fault.

This was the main reasoning for choosing the photos I did.   Everything I took pictures of had symmetry but only a few had the right composition.  Really I only used one photo who's form I thought was less than perfect and that was the ripples in the water that you can see to the left.  The ripples were so hard to catch since they only last for a split second and then there was the problem of other ripples.  I tried to create my own but having to throw water was too hard to get back into position to take a good picture in time.  So, since I really wanted to show the water ripples I settled for less than what I wanted.

Quite a few were not chosen because the symmetry was hard to display as in the picture below.  It just looks chaotic.