How can one trick LaTeX to believe that a given page is odd instead of even?
Or alternatively call the odd-page header in a previously defined pagestyle?
\thispagestyle{Somehow-define-that-i-want-odd-page-style-from-"fancy"}
The document class used is book.
Very simple — just insert \cleardoublepage, which will start a new odd page (inserting a blank page before if necessary).
Some structuring commands in the book document class insert \cleardoublepage by themselves if the openright option (on by default) is enabled, such as:
\frontmatter
\mainmatter
\backmatter
\part
\chapter
…
