Prior to Tableau 10, all formatting was done on a worksheet by worksheet basis. Tableau Desktop now has a concept of “workbook formatting” which become the default for any new worksheet. Each version of Tableau is bringing more formatting options into the scope of workbook formatting (for example, line formatting is being added in 10.2), but not everything is available yet.
Make a Template Worksheet and Dashboard
For any option available in workbook formatting, you should set it there (in the Format->Workbook menu at the top). For other things, like background shading, you should create both a template worksheet and a template workbook.
For the template worksheet, I suggest creating a Calculated Field with a simple message indicating that it is a template to be copied. Drag the field onto Text and change the fill type selector at the top from “Standard” to “Entire View” to make your message show up. Use the Format->Worksheet menu to set everything you’d like.
Next make a template dashboard the same way, and drag out the Template Worksheet. In the end, it will look something like this:
Now publish it to Tableau Server. Rather than having users start their ad hoc analysis from a Data Source, have them start from the Ad Hoc Template Workbook. When they Save As to a new workbook, they can delete the templates sheet and dashboard because the new sheets will have that formatting which they can duplicate from.