Here are some simple icon designs. I like how easy clean they are and each one has a specific opening to it that allows the icon to be a part of the background. I also like how they are all see through and tie in well the background also.
I love this! Here we have one idea: a tree. But you have a few basic shapes that make up so many combinations. However, they all read the same way: a tree. A few small elements can become many different compositions. So many possibilities.