Odd numbered pages should always be right pages!
So you should always use \cleardoublepage before changing page numbering, because it makes no sense to change page numbering on the left side of a double sided print:
\documentclass[twoside]{article}% It's better to tell already the class to use twoside!
\usepackage[showframe]{geometry}
\begin{document}
This is the first page; it should be a right page (recto).
\cleardoublepage
\pagenumbering{arabic}
This is the third page; it should be a right page, because changing page numbering should always be done on right pages!
\end{document}
If you simply wanted to suppress page number at the first page of an article, try:
\documentclass[twoside]{article}% It's better to tell already the class to use twoside!
\usepackage[showframe]{geometry}
\begin{document}
\title{Title}
\author{Me}
\maketitle\thispagestyle{empty}
\begin{abstract}A short abstract of the document.\end{abstract}
Some more text, e.g. a table of contents.
\clearpage
This is the second page; it should be a left page and numbered 2!
\end{document}
Note: You may use \cleardoublepage before \pagenumbering even at oneside documents, because in this case it would have the same result \clearpage would have.
But, if you really, really must have odd pages left and even pages right, you may simply switch the margins (and the margin used for \marginpar):
\documentclass[twoside]{article}% It's better to tell already the class to use twoside!
\usepackage[showframe]{geometry}
\makeatletter
\newcommand*{\flipmargins}{%
\clearpage
\setlength{\@tempdima}{\oddsidemargin}%
\setlength{\oddsidemargin}{\evensidemargin}%
\setlength{\evensidemargin}{\@tempdima}%
\if@reversemargin
\normalmarginpar
\else
\reversemarginpar
\fi
}
\makeatother
\begin{document}
This is the first page; it should be a right page (recto).
\flipmargins
\pagenumbering{roman}
This is the second page; it should be a left page (verso).
\end{document}
Using a page style like headings you may also need to change the page style, e.g., to print the numbers near the outer margin. You may do this, using either scrpage2 or fancyhrd. Here an example using scrpage2:
\documentclass[twoside]{article}% It's better to tell already the class to use twoside!
\usepackage[showframe]{geometry}
\usepackage[automark]{scrpage2}
\pagestyle{scrheadings}
\makeatletter
\newcommand*{\flipmargins}{%
\clearpage
\setlength{\@tempdima}{\oddsidemargin}%
\setlength{\oddsidemargin}{\evensidemargin}%
\setlength{\evensidemargin}{\@tempdima}%
\if@reversemargin
\normalmarginpar
\else
\reversemarginpar
\fi
\ifdim \evensidemargin>\oddsidemargin
\ihead{\headmark}%
\ohead[\pagemark]{\pagemark}%
\else
\ihead[\pagemark]{\pagemark}%
\ohead{\headmark}%
\fi
}
\makeatother
\begin{document}
\section{Normal pages}
This is the first page; it should be a right page (recto).
\flipmargins
\pagenumbering{roman}
\section{Inverse margin pages}
This is the second page; it should be a left page (verso).
\end{document}
Alternative:
One completely different alternative would be to fake the page number, given by \thepage:
\documentclass[twoside]{article}% It's better to tell already the class to use twoside!
\usepackage[showframe]{geometry}
\makeatletter
\newcommand{\@arabicplusone}[1]{\@arabic{\numexpr #1+1\relax}}
\newcommand{\@romanplusone}[1]{\@roman{\numexpr #1+1\relax}}
\newcommand{\@Romanplusone}[1]{\@Roman{\numexpr #1+1\relax}}
\newcommand{\@alphplusone}[1]{\@alph{\numexpr #1+1\relax}}
\newcommand{\@Alphplusone}[1]{\@Alph{\numexpr #1+1\relax}}
\makeatother
\newcommand*{\pagenumberingplusone}[1]{%
\pagenumbering{#1plusone}\setcounter{page}{0}%
}
\begin{document}
This is the first page; it should be a right page (recto). See
page~\pageref{test}.
\clearpage\pagenumberingplusone{roman}
This\label{test} is the second page; it should be a left page (verso).
\end{document}
Disadvantage of this suggestion would be, that if a package uses page counter directly for something else but testing odd or even the result may be unexpected. The advantage of this suggestion would be, that pages with odd value of counter page shows not only an even page number but will be handled to be a even=left page by LaTeX and every class or package that uses \c@page or \value{page} for the test (and vica versa).
I'm quoting this answer from stackoverflow:
For debugging page layout, Peter Wilson's layouts package is the way to go. Here's an example for visualising the page design and seeing the dimensions used for it
\documentclass[a4paper,12pt]{report}% I didn't add the twoside option in order to only display the right page layouts
\usepackage{layouts}
\usepackage{geometry}
\begin{document}
First you see the default page layout:
\currentpage
\pagedesign
\clearpage
\newgeometry{text={155mm, 24cm}, top=25mm}
Now you can check the page layout you passed to geometry:
\currentpage
\pagedesign
\clearpage
\newgeometry{inner=16.5mm,outer=11mm,top=25mm}
and then check the possible layout you expected (I'm assuming you're using A4 paper)
\currentpage
\pagedesign
\clearpage
\end{document}
As you can see (from the first layout displayed), the default page layout for report (and the other default classes), as @egreg pointed out, does define an outer margin larger than the ineer one.
Since you jest passed to geometry the format for the body (with the text={<textwidth, textheight>} option), it doesn't change the page's default, just adjusting itself to it. In order to achieve what you expect, you must tell geometry what is the inner and outer margins lengths you expect. You can do that both with inner and outer options or with left and right (or lmargin, rmargim, check geometry doc, p. 9)
EDIT: Just updating, following @daleif's comment:
It's considered good typographical practice to use larger outer margins and smaller spines — for the sake of tradition or just to provide the reader a space for personal notes. There's a a wonderfully complete answer explaining that, by Yannis Lazarides (Actually, that question is closely related to yours).
Best Answer
If I run this sample document
I get, in the log file and on the console, the relevant lengths:
Rounding
\headsepis irrelevant, so I'll use 18pt:This prints
which agrees with the standard setup.
With
\documentclass[11pt,a4paper]{book}(thetwosideandopenrightoptions are on by default), the values obtained in the first step areso the change should be
with this setup I get as output
Note that, in any case, LaTeX just looks at the values of
\topmargin,\headheight,\headsepand\textheight; the bottom margin is whatever remains.This is the output I get for the first page with the new settings
and this is the output without loading
geometry