The briefing can be conducted face to face, by phone, or email. Either locally, interstate, or internationally the basic process is the same. it may be of interest that a great many of my clients I have never met face to face.
Typically just forward the design documents you have available relative to where you are in your design process. On occasion this is only a verbal description or some indicative images for master planning images.
Indicate the general viewing positions you think you may require, any critical design issues that need to be considered.
This is normally enough to get your project underway.