I am currently involved with one client's less frequent deployment cycle. They are looking to move to a more flexible and frequent delivery but they have a reasonably large connection of related system. They are in an industry that is heavily regulated which adds its own complications.
The first step is continuous integration (CI) as without it the development teams cannot have the confidence in the build.
Next step, in my opinion, a higher coverage level by automated testing azs part of the CI.
-- Stop your grinnin' and drop your linen...they're everywhere!!!