How to center Slider, and youtube videos

Hi guys!

I’m using the New Royalslider on on of my pages, but right now the slider is in the left side of the page, I want it to be centered – I have inserted the slider via a shortcode, so how do I center it?

And another question: I have also inserted youtube videos, i’ve just inserted the video-link on the page; so how do I center the videos?

Regards