If you can't think of a new project to work on right now, consider contributing to an open source project that needs help. Simply getting started on something will usually get your creativity flowing and ideas will come.
I am thinking to contribute to open source project for a long time but I can not find courage to do that because contribute to open source project is look like very difficult to me, I can start to read and understand the toy projects but I can not find the way for understanding and contributing big projects like mozilla firefox or pyton.