- Combine what you've learned into a complete, full stack project.
- Learn and incorporate new technologies and techniques.
- Learn how to build a complex software system.
- Consider the maintenance effort that grows as a part of building this system.
- Stick to languages/frameworks you're familiar with. (You can always come back and build it in another framework later.)
- "Do one thing that scares you" - Once you've got the basic functionality down, pick one thing you don't know how to do and learn how to do it (e.g. Authentication with PassportJS)