Phone face down. Glance at the tell card before you start if you need to, then put it away. You're telling, not reading.
Slow down. Whatever pace feels right, go slower. Bedtime voice is lower and quieter, and it gets quieter as the story goes on.
Pause before the big moment. "And when Hector turned around..." (wait) "...Achilles was already there." Silence is your best tool.
Change your voice a little, not a lot. A deeper voice for the giant, a whisper for the secret. You don't need to act; small changes are enough.
Use their world. "Achilles could run faster than anyone, faster than you on your bike down the hill." One comparison like that does more than a paragraph of description.
Let them interrupt. Questions mid-story mean they're in it. Answer briefly and carry on: "Good question. Hold that thought, watch what happens."
Eye contact on the important lines. Look at them when the hero makes the choice.