Think offscreen, too

When you establish the situation, answer questions, or make moves, think about events off-screen. What are your NPCs and monsters doing? What have they done? What traces did they leave? What have they been up to that becomes evident? What are they doing now that might become relevant later? Weave the answers into what you say.

Think, too, about what the PCs are doing and how it would shape off-screen events. If they make a lot of noise moving through the Great Wood, who hears them coming and how do they react? If they make an alliance with Gordin's Delve, how do the Hillfolk who have a beef with the Delvers—respond? If they told the town that they'd be gone for five days and they're gone for two weeks, who assumes that they're dead? Who steps up and tries to take charge? Who takes the opportunity to do what they want?

Thinking offscreen helps you portray a rich and mysterious world, because the world will feel larger than the PCs. It helps you punctuate the characters' lives with adventure, because off-screen threats and opportunities quickly become things for the PCs to deal with. And it helps you play to find out what happens, because it gets you thinking about consequences and cause/effect on a broader scale.