It's not treated like a design project
As mentioned earlier, it's imperative to start with organized content that makes the value of the information clear, just as any other design project would begin. It is important for the designer or designers to have this content structure, especially if they are new to your brand style, but it's key in the process even if they are familiar with your branding. The design should be driven by the content.
Art and copy don't go together
Also like any design project, the marriage of art and copy is paramount. This is the pinnacle of concept deployment and understanding. Select visuals that are relevant to the story. It sounds a bit obvious, but based on some of the strangely metaphorical infographics out there, it needs to be said.
This is the not the type of project to be using metaphors, abstract representations, or complicated illustrations. It's better to keep things clean. If the data is about favorite beers, use simple images of ales or frosty mugs that are easily discernible as beer. Don't use two men holding bottles in a store alongside a family at the check-out with groceries. That could be about any number of things unrelated to selecting beer. Like any other design project, art and copy should work in tandem to reinforce each other without needing to entirely describe what one another is expressing.