Social media (goodreads/tiktok/reddit)? Colleagues? Friends? Browsing the library/bookstore? Asking for recommendations from staff at libraries/bookstores?
BONUS: if you can remember, how did you find books you really enjoyed?
I realized a lot of my favorite book recs came from reddit. I was a subscriber of r/books and picked up some really good books there. Piranesi by Susanna Clarke is an example.
I realize you are asking books and not necessarily audiobooks but for audiobooks I follow a few good narrators that I know only do books I will like. This way I am almost always guaranteed a good book, and as a bonus I already know the narration quality will be perfect.