Review your notes when you finish the book. Review your notes one day later and also one week later. Keep up with periodicals in your field. Books are your best source for comprehensive information, but the lead time for a book to go to press means that books are out of date before they hit the shelves. Periodicals are required to round out your knowledge base.
Public libraries subscribe to many periodicals.
Many industry periodicals are available free to qualified subscribers. Wander the Web. Each time you find a link to something that sounds interesting, follow that link. Practice, Practice, Practice. Reading Is Fundamental, but reading isn't everything.