All artists are collectors of ideas, and as you are only going to be as good as the stuff you surround yourself with, all good artists are collectors of good ideas. The more good ideas you collect, the more sources you can draw upon for creative inspiration.
Read, watch and listen to things that fuel your imagination.
Surround yourself with new films, old films, music, books, paintings, photographs, etc.—basically, anything that drives your creativity. After all, you should create what you like, and therefore, you should draw inspiration from what you like.
Learn from your role models.
Pick one thinker (a writer, artist, activist, etc.) that you love and look up to. Study everything there is to know about them, then study the people this thinker loved and so on. Add yourself to this lineage of thinkers and build on the knowledge they already had to create your own masterpiece.
Be curious about the world you live in. Google everything, read more, search for new things. Write your thoughts and findings down in a notebook and come back to it later.
Follow the best people online.
Follow people smarter and better than you and pay attention to what they talk about and what they do. Be kind—answer questions they’ve asked, write them a “fan letter,” etc.
Have a few side projects and hobbies.
When you’re sick of one project, move to another one and work on that until you’re sick of that one too, then go back to your first project. Or, engage in a hobby you enjoy. You’ll improve your productivity and keep your brain occupied with constructive thoughts.