Create a YouTube Video Template

In "Embedded Media Editor", create your templates for Youtube videos by selecting "YouTube" from the "Media Type" dropdown. Then configure the width, height and border of the embedded media.

Click "Update" to save the changes.

Insert a YouTube Video

Now you can open a CKEditor, click the button to insert an embedded media, and choose a template you created to insert a Youtube media. Put in the ID of your video.

Hit "Save" to confirm, and you will see the media showing up in the editor!