Imagine being a chef who only eats chicken nuggets, a carpenter who refuses to look at buildings straight on, or an orchestra conductor who doesn't listen to anything but commercial jingles. Such is the problem for a writer who doesn't read regularly and widely.
Books are the maps to your craft.
Reading like a writer requires you to figure out what in a piece of fiction moves you and what turns you off. I'm calling that self-awareness your narrative detective—its job is to solve the mystery of the narrative, looking at the ways it is and isn't succeeding—and I'm going to encourage you to feed it PIE every time you read anything: a menu, a short story, the interpretive plaque next to the world's biggest redwood tree.
Here's the ingredients to the PIE:
P: prepare with pen and paper. In other words, always have a notebook and something to write with nearby when you read. Be prepared for insight. A writer cannot simply read for pleasure. S/he uses every word as research.
I: immerse. Get inside the words, the sentences, the story arc. Don't simply stay on the surface of what you're reading, no matter how shallow it seems. Go deep.
E: examine. If that cereal box makes you excited to eat the Sugar Doodles, ask yourself what it is about the words and their formatting is doing that for you. If you read that redwood plaque and walk away feeling smart, ask yourself how it pierced your busy mind. If—especially if—you're reading a book, and you connect with a character, or you find yourself yanked out of the story, or you read a sentence twice to savor the citrus taste of it, study that shit like a lover's face. Write down what you think is happening ("main character makes stupid choices," "too many adverbs," "lots of smell detail drops me straight into the story," "each chapter ends with a hook," etc.) because transcribing information flips a switch in our brain, waking up the records guy who then goes over to pick up what you wrote and file it somewhere so you can access it later.
When you feed your narrative detective PIE, she begins to internalize the language and rhythm of story. The results, like magic, will begin to show up in your own writing.