Jenna Coleman has offered some amusing advice to the new Doctor Who co-lead Pearl Mackie.

Speaking ahead of the show's return, Mackie said that the fellow actress, who left her role as Clara Oswald in 2015, sent her flowers on her first day of filming along with some tips for the show.

"Practice your superhero run to comedy theme music," was apparently a key piece of advice Oswald had for the Doctor's new companion, RadioTimes reports.

Apparently the best way to perfect those scenes of constant running away from monsters is to play some funny music.

"[She also told me[ stuff like where to get nice food delivered in Cardiff, and what not to eat in the canteen," Mackie said. "Anything in the canteen!"

Speaking about her character Bill and previous companions, Mackie elaborated after her revelation that she had been told not to watch other companion performances so she wasn't too influenced for her own.

Jenna Coleman as Clara Oswald in the Doctor Who Christmas special (BBC)

"Obviously every companion is completely different," she said. "But essentially there is a similarity between them, because they travel with [the Doctor]. So watching someone do the job that you're about to do, brilliantly - all the companions have been amazing - you'd be mad as an actor not to go 'Oh that's good, I'm gonna have that'.

"So I thought obviously what I was doing in the audition was working, and I thought even subconsciously I wouldn't be able to stop myself from borrowing things from previous companions. So perhaps it is best to not do that, so I can continue being Bill as I would play her."

Fans have interpreted the new trailer for the BBC sci-fi series as a hint that Mackie's character Bill may not actually be around for too long.

In the teaser she says: "I'm having the time of my life - and I wouldn't miss it for the world..." before the ominous: "Even if it kills me."

Separate rumours have suggested that she may leave Doctor Who after just one series as a companion, which would give new showrunner Chris Chibnall a fresh start when Peter Capaldi also leaves as the 12th Doctor - along with current head writer Steven Moffat.