Players have the most fun when they roleplay as their characters, not when they listen to the GM telling a story.

So the best thing you can do to engage your players is to learn how to guide your players' improv, as opposed to narrating everything yourself. Aim to let the players drive the story as much as you can, encourage them to do most of the talking, describe things in awesome ways, roleplay with each other.

But many players struggle to improvise and describe things. How can you help?

Asking leading questions is the most powerful tool you can use to draw your players into the story and guide their improvisation.

You can use questions to help players create vivid descriptions:

• What does your [costume, sword, house, pet] look like?
• How do you [cast a spell, attack the orc, sneak through the shadows]?
• Describe to me, how do you [do the thing the player wants to roll for]?
• How do you [help another player to give them advantage on a roll]?

And to add details to the world around them:

• What's an unusual detail that you notice about [this place, monster, item]?
• Do you know anything about [the place or a creature you have encountered that the character might be familiar with]?

Encourage players to contribute to the story and drive the plot forward:

• What do you want to do next?
• On a successful roll, ask the player to narrate the entire outcome.

Help players to develop their characters and get into their role:

• How do you feel about [the situation you're in]?
• What’s going through your head as you do [some dramatic or dangerous thing, have a confrontation with another character]?

Prompt them to interact with each other:

• How do you react [in response to another player's action, when you pick up on another player's emotions]? What do you say to them?
• You notice [some important information, some detail other players can't see]. Do you share it with a party or keep it secret?

If you notice your players struggling to answer the question - you can give them multiple options to choose from, or build on top of their ideas to help them make their answers more awesome.