When I started to really get into photography, the book that did wonders for my learning was "Understanding Exposure", by Bryan Peterson.
In a part of the book that talks about composing shots; he shows an example of a flower taken at a low angle, and showing the light passing through it. It's a picture that has always stuck with me. And it constantly reminds to look at things in a different perspective.
Italy Pavilion EPCOT World Showcase