Using Smush Pro with WP Retina 2x

I just installed Smush Pro. Doing a bulk smush of my entire media library seems straightforward. But in your description, you mention that Smush is integrated with WP Retina 2x plugin. So installed that too. But now I'm wondering what the proper protocol is for smushing the entire library and bulk generating retina images at the same time.

What exact steps should I follow to get the best results -- both smushing and retina-izing in one bulk process?

Thanks!