Create a new workbook and save it as book.xlt (a real template file) in your
XLStart folder. Change all the settings you want for each of the worksheets you
want.
Then excel will use that when you create a new workbook by clicking on the new
icon on the standard toolbar.
This doesn't change any page settings for any existing workbook.
You can also create a template file named sheet.xlt with the same kind of
settings. Store this in your XLStart folder, too.
Then any new worksheet added to an existing workbook will inherit these
settings.