Those blank pages

In the book class when the openany option is not given or in the report class when the openright option is given, chapters start at odd-numbered pages, half of the time causing a blank page to be inserted. Some people prefer this page to be completely empty, i.e. without headers and footers. This cannot be done with \thispagestyle as this command would have to be issued on the previous page. There is, however, no magic necessary to get this done:

\clearpage{\pagestyle{empty}\cleardoublepage}

As the \pagestyle{empty} is enclosed in a group it only affects the page that may be generated by the \cleardoublepage. You can of course put the above in a private command. If you want to have this done automatically at each chapter start or when you want some other text on the page then you must redefine the \cleardoublepage command.

\makeatletter
\def\cleardoublepage{\clearpage\if@twoside \ifodd\c@page\else
  \hbox{}
  \vspace*{\fill}
  \begin{center}
    This page intentionally contains only this sentence.
  \end{center}
  \vspace{\fill}
  \thispagestyle{empty}
  \newpage
  \if@twocolumn\hbox{}\newpage\fi\fi\fi}
\makeatother