Dr. Joe Russell T. Davis gets his ideas by brushing his teeth.

Some writers get their creative juices flowing when they bounce ideas off a friend.

Others may cast spells while staring out the bus window.

Now Dr. Joe showrunner Russell T. Davis has revealed his success secret, which is an important part of his morning routine.

“Honestly I swear to you,” said the 61-year-old, brushing his teeth.

“I think everything works in my head overnight.

“And you wake up, and you brush your teeth and things click into place.”

He compared coming up with ideas like this to the game Wordle.

“You know, leave it for an hour, and all of a sudden the word comes out,” Davis recounted Behnaz Akhgar of Radio Wales.

“I wonder a lot if life is like that. Your subconscious goes ‘click, click, click’ and ticks through all the algorithms and ideas.

“So brushing your teeth, honestly, sometimes things go ‘boom, boom, boom.’

“I’ve thought about whole shows brushing my teeth.”

When it comes to putting pen to paper, Davis shuts himself down.

He said that I am very suspicious of those people who sit in the cafe.

Although it’s been nearly 20 years since Doctor Who returned to TV screens in 2005, Davies still gets nervous before a broadcast.

The latest Christmas episode of the series is being shown on Christmas Day on BBC One.

The episode titled Joy to the World is about a hotel where each room has a different world.

“You feel the pressure and you feel it’s part of the job,” he said.

“You get scared, you don’t want to be disappointed.

“You get to say something new, you get to have an impact, so that’s a lot of fuel for the engine.”

The Christmas show will feature fellow Derry Girls and Bridgerton star Nicola Coughlin.

“She knows Dr. Nikoti Gutwa, and they were both in the Barbie movie,” Davis said.

“On social media, they like to chat, and they get to know each other in this crazy social world that actors live in.

“So it was an offer that he accepted very quickly. We’re happy.”

Davis is also working on a Doctor Who spin-off. Battle between land and sea.

He said: “It’s a different show, it doesn’t have the Doctor. We’ve done it over the years. There was Torchwood, which was set in Cardiff and The Sarah Jane Adventures.”

The new series stars Russell Tovey and Gugu Mbatha-Raw.

In it, an ancient race emerges from the sea, creating an international crisis.

Davis said: “When you look and see what we’ve done to our oceans, if you lived in the ocean, if there were such a thing as sea creatures, wouldn’t you be outraged?

“Haven’t we ruined them?”

The Doctor Who Christmas special is on iPlayer and BBC One from 17:10 GMT on Christmas Day