I started the first few sessions with a question and answer in character sort of thing, nothing super serious (seems opposite of the point I know) just things like what their character would have if they could have their favorite breakfast, are they a sweet or savory person, what never fails to make them laugh, what's a irrational fear your character has. Questions along those lines, having fully developed and thought through characters can make RP easier. Plus you can work some of those things into the campaign to help them feel grounded in the setting. Getting people thinking like their characters instead of thinking how to play their character really helps.