Insert a blank page after current page

You should use the afterpage package.

In the preamble :

\usepackage{afterpage}

\newcommand\blankpage{%
    \null
    \thispagestyle{empty}%
    \addtocounter{page}{-1}%
    \newpage}

In the text before the blank page, insert the following code:

\afterpage{\blankpage}

It should do the trick. Be aware that unresolved floats might be a trouble here.

You just need something – anything – before or after the \newpage command. Try

\afterpage{\null\newpage}

Of course, this doesn’t remove page numbers or headers and footers, and it does increase the page number. If you don’t want this, see Martigan’s solution.

I think you can avoid using the afterpage package. In the preamble, write:

\def\blankpage{%
      \clearpage%
      \thispagestyle{empty}%
      \addtocounter{page}{-1}%
      \null%
      \clearpage}

In the document environment, use the \blankpage command to add blank pages without style or counting.