As a student I made a set of 60 icons for a school assignment. I was given 5 key words and then designed icons so they had those traits. My keywords were dynamic, open, textured, realism and light
I decided to tilt each icon by 15 degrees to create a symplistic sense of movement. I also put every icon on a background square that the icon seemed to be "escaping" to create an open feeling. Finally I added a light grainy texture and shadows to get the textured and realism traits across.
This image is from back when I was still working on it. I hadn't quite figured out the texture yet.