Our Tableau Server users often compliment us about the fact we have a common corporate branding applied to all of our Tableau Workbooks; they say this makes it easier for them to use Workbooks as they learn more quickly through the common design and it gives them confidence when viewing a viz that looks professional and links back to the style of the wider organisation.
One of the ways we have achieved this is through the creation of a style guide that has helped guide our analysts through the basic design principles of a workbook, for instance the footer, the header, the fonts and colour palette to use. To help others implement a similar approach I have shared our style guide as part of my latest blog post:
The style guide has been shared in Word so you can download it and adapt it for your own organisation should you so wish; if you do would it would be great get a quick shout out on twitter acknowledging the work we have done (@simonbeaumont04)
I hope you find the style guide useful.