When you design a marketing campaign, think of it as architecture. Think of your communications pieces as having an architectural style.
This way you can stick with a theme. For example: modern architecture. This would be similar to the clean, short bursts of information a la Seth Godin, when it comes to written content, and a la Apple when it comes to everything (images, color schemes, video, written content, overall feel, etc).
Consider which style you most relate to:
Victorian: the conservative, buttoned up yet decorous style of Liberty or St. Pancras Train Station or arguably (although it's technically Queen Anne Revival but close enough for this discussion) Harrods
Craftsman: a new world blend of function and form, with an "outdoors" timbre, like the marketing style of Ralph Lauren
Glamping tents: Higher end outdoorsy brands like Patagonia (so-called "Patagucci")
Southwestern: not overwrought, desert tones, and with slightly rugged structure, sometimes with decorative nods to Native cultures, a la the Taos Pueblo and Georgia O'Keeffe's brand
Of course there are many more. Hone in on one style you like -- and stick with it.
Rococo style images and communications would be bursting with detail, use sumptuous wording, and end in luxurious flourishes.
Craftsman messages would be warmer, shorter and to the point.
You have the idea.
Just continue to build on it.