I found this "Umbraco Skins" guide dated of 12/23/2010 which is an excelent start on the skinning subject.
However, it doesn't mention mvc/razor (probably not available at that time).

Is there support to skinning when working with razor templates (views) instead of master pages?
If yes, is there any special consideration or is it the same from this 2010 document?

The pdf is available here: http://umbraco.codeplex.com/documentation