til / learn by doing side projects
I can honestly say that building a bunch of side projects has made me a better developer. I get to actively work on different problems, try new things and improve my knowledge.
Have one specific project, a project you know exactly how you want it to work, to test out new ideas, technologies, and frameworks on. If it contains multiple parts, like interacting with an API or how to contain state, it's a perfect project to evaluate new technologies with.
You can potentially learn even more by Learning in public.