Core knowledge. Create an environment that encourages a love of reading as soon as possible and help them develop core knowledge about the world around them. This includes both language and facts/concepts about everything from ancient history to the solar system.
Domain-specific background knowledge is incredibly important. It turns out (for the most part) there are no general purpose cognitive skills... it's all domain specific. A student that knows about baseball will comprehend an article about baseball much better than one that doesn't have the core knowledge of what a run, base, double, home run, etc. means. Decoding strategies be damned.
Helping your young child develop said background knowledge will put them in a fantastic spot as they enter school. They'll 'get the joke' - it's a bit like velcro for the brain. Nothing sticks for the students that enter school without the cognitive velcro that is domain-specific background knowledge.
I know this sounds completely contrary to the progressive education philosophies that domain our culture about teaching kids how to think vs what to think... no memorization, etc. It surprised me too.
Check out the work of cognitive scientist Daniel T. Willingham, Natalie Wexler (The Knowledge gap is a great book) or E.D. Hirsch for a deep dive.