If you're fortunate enough to have an employer that encourages this practice, (ask them if you're not sure) they may help you out with the costs of attending conferences, buying textbooks, taking classes, getting certified, etc. In theory, their return on investment should be quite high for this.
But even if you're a freelancer (or work a job that doesn't promote life-long learning) there's still quite a bit you can do. My big 4 are: Meetups, conferences, whitepapers/articles/books, and the occasional class (either online or in person). Some of these cost money, others don't. But once you make them part of your normal routine, it'll feel like second nature. You'll look back with utter contempt on those days when your skillset stayed stagnant for months.