Novels with illustrations in moderation. It used to be fairly common years ago to have complete pages of art, and it's still a thing today even if not as often. There's a reason novel readers pick up novels instead of comics, though, so just don't overdue it.
Once in a while, it's nice to have a visual, like a map or a scene or maybe an object that has been mentioned and is very important to understand its appearance. Otherwise, let the reader use their imagination. Give them the tools with descriptions, but let them fill in the rest so they can feel engrossed in the story.
