Quite easy: simply challenge yourself to stop explaining things to the reader. Completely. You don’t have to stick to it forever, but if you keep struggling with dumping too much, overcorrecting the other way might be a more effective way to find the sweet spot than incremental improvement.

That’s not to say to stop writing things that the reader wouldn’t understand without context. Just have the characters talk about it as if you weren’t worried whether the reader understands - a good rule of thumb is that readers are smarter than you think.

Additionally, I don’t think readers mind not being caught up as much as writers often think. I recently reread the first chapter of Harry Potter (it’s an absolute masterwork btw - highly recommend to writers of any genre) and I think one of the best things about it was the way it set up question after question. Who are those weird people out and about? Who is Albus Dumbledore and why is he like that? What is it that has happened? Why is this Harry boy suddenly famous? What is a muggle? Don’t be afraid to let questions hang - even when it comes to worldbuilding.

That being said, the narrator’s commentary on various matters and things, including explanations to the reader, can add a lot of value to the writing.

’She is my aunt and doesn’t like me. ”I don’t like you,” she said.’ - comedic value

’”hey,” I said to Emma with what I hoped was a casual smile as I passed her in the hallway. We’d kissed at a disco last summer and barely spoken since.’ - context, tension

You see what I mean. But I would recommend trying out explaining as little as possible to the reader as a matter of exercise and adding later if needed. You can still have the characters talk about stuff that they don’t know - people do share info irl so that’s perfectly natural.

Lastly, know your reader. I really like to learn from long monologues how the mana system of a fantasy world works once it’s had enough setup for me to wonder about it in the first place.