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.
Along with what others have said, I consult the list of Noble and Pulitzer prize winners. Not all of them are great, as to be expected, but many of the best books I’ve ever read are on them.