Personally I give each character a face, either from a person I know who matches their personality or a celebrity that fits the description, even though sometimes it can be really annoying if the author gives more details on the persons appearance and my character doesn’t fit that lol. I’m very curious as to what other people do.
The books I love most are those that bring me into the lives of the characters. And I am open to picturing the characters the way the author describes them. That’s what I love - to be drawn into another world and the stories and people from that world.