They're both British and speak British English. Try this course to better understand and improve your individual sounds http://www.bbc.co.uk/learningenglish/english/features/pronunciation. To improve your pronunciation in connected speech, I'd recommend to use any videos at BBC Learning English or YouTube (you could even find Emma Watson's or Toby Regbo's videos). What you need to do is listen to a phrase or a sentence in a video, then stop the video and repeat what you heard. Try to copy the accent as close as you can. If you're not happy after your your first attempt, do it again (..and again...and again))). Practice like this regularly and you'll hear the results pretty soon.

Emma Watson - RP Toby Regbo - london accent

Thank you all, all great advice ! Will check out your suggestions to see which is my favourite

I've just listened to Toby for the first time. He's got a typical, South East English or London accent as Georgiy pointed out. I agree that Emma Watson's accent can be considered a bit "posher" and is RP (received pronunciation). You might want to listen to actors like Robert Pattinson or Emma Thompson as they all have similar South-East of England/RP accents. @Halyna Semenko's advice is good - the pronunciation videos on the BBC website are excellent. really clear and they show you exactly how to pronounce the sounds physically.

She is British so it would be great to search for a British language partner :)