What's the best web development process for a CMS website?

For creating online reservation systems and e-commerce websites i can easily reuse the wire-frame of a previous project, but for a Content Management System projects it seems like i have to start from scratch because i have to base the wireframe from the existing website of the client or from an approved homepage and inner pages design.

Do i just design the backend wireframe and leave it up to the developers to figure how it's going to work in the Front end? Do i design a wireframe for both the BE and FE? Is the wireframe really supposed to be final before it goes to the development? Should you create the wireframe before the design?

What's your take on this? Kindly advice me on how to go about this.

Thanks in advance for your reply.