Here’s a precise manual I put together for convenient learning of LaTeX document writing and as an easy reference. Bookmark or re-download periodically as I will keep updating this page for improvement.

\[\\[0.2in]\]

Document-class settings

Set document-class

% class article for articles in scientific journals, presentations, short reports, program documentation
\documentclass[14pt]{article}

% use extarticle class for getting font sizes 8pt, 9pt, 10pt, 11pt, 12pt, 14pt, 17pt, 20pt
\documentclass[14pt]{extarticle} 

% class beamer for presentations
\documentclass{beamer}
\documentclass[t]{beamer}  % aligns text on top of the page

% class memoir for fiction, non-fiction and mathematical books  
\documentclass[17pt,twoside,onecolumn,extrafontsizes]{memoir}

% class book for books
\documentclass{book}

\[\\[0.4in]\]

Page and Text settings

Set page and text area / margins / header-footer

\setlength{\topmargin}{-1cm}
\setlength{\oddsidemargin}{0in}
\setlength{\evensidemargin}{0in}
\setlength{\textwidth}{6.5in}
\setlength{\textheight}{8.7in}
\setheadfoot{\baselineskip}{0pt}  %for memoir documentclass
\setlength{\footskip}{9pt}

Set / change document font

\usepackage{fontspec} % Need to run with XeLaTeX or LuaLaTeX
\setmainfont{Times New Roman}  %Arial, Georgia, Baskerville, Times New Roman, Calibri, Lucida Grande, Verdana

Add header on each page

\usepackage{fancyhdr} 
\pagestyle{fancy}

Link contents in page header

\fancyhead[R]{ \hyperlink{TOC}{Contents} }

Change page background color

\usepackage{pagecolor}  %command \pagecolor{} must be loaded after package color or xcolor
\pagecolor{gray!10}

Define colors

\usepackage{color, colortbl}
\definecolor{lg}{rgb}{.69,1,.40}  % define new color lg using rgb soecs
\definecolor{lp}{rgb}{1,.80,.11}

Insert page background

\usepackage{background}
\backgroundsetup{
scale=1,
color=black,
opacity=0.2,
angle=0,
contents={%
  \includegraphics[width=\paperwidth,height=\paperheight]{background.jpg}
  }%
}

Insert a landscape page somewhere

\usepackage{pdflscape} 
\begin{landscape}
…
\end{landscape}

\[\\[0.4in]\]

Beamer presentation

Title page

\title{}
\date{\today \vspace{-5pt}}
\author[Nilotpal Sanyal]{Nilotpal Sanyal}
\institute[ISI, Kolkata]{Indian Statistical Institute, Kolkata}
\titlegraphic{\hspace{-212pt}\vspace*{-10pt}\includegraphics[width=0.5\textwidth]{mallat_coverpic.jpg}}
\logo{\includegraphics[width=25pt]{ISI_logo.png}}

\begin{document}
\frame[plain]{\titlepage}

Add frame

\frame{ \frametitle{}

}

\[\\[0.4in]\]

Line and Paragraph settings

Set line and paragraph spacing/breaking

\setlength{\parindent}{0.5in}
\setlength{\parskip}{.6cm}
\renewcommand{\baselinestretch}{1}
\tolerance=500

Indent first paragraph of a section

\usepackage{indentfirst}

To obey the natural linebreaks in the text

First select all text, do Source–>Wrap–>Hard wrap. Then wrap text within obeylines environment

\usepackage{parselines} 
\begin{obeylines} 
... 
\end{obeylines}

Spacing at the beginning of a line

\hspace*{20pt}

Linebreak after paragraph name

\paragraph{bla} \mbox{} \\
bla bla bla

\[\\[0.4in]\]

Text formatting and display

To underline multiline text

\usepackage{ulem}
\uline{text}

%or

\usepackage{soul}
\ul{text}

Allow spacing in itemize/enumerate

\usepackage{enumitem}

Set enumerate/itemize topsep and leftmargin

\usepackage{enumitem} 
\begin{itemize}[topsep=0pt, leftmargin=0pt, itemsep=2pt, parsep=4pt]
…
\end{itemize}

Make nested itemize

\usepackage{outlines}  
\begin{outline}
\1
 \2
  \3
\1
\end{outline}

Use various characters and symbols

\usepackage{pifont}
\newcommand{\cmark}{\ding{51}}
\newcommand{\xmark}{\ding{55}}

To hide/show text

% write in preamble
% To hide/unhide proofs
\newif\ifhideproofs
\hideproofstrue %uncomment to hide proofs
\ifhideproofs %hide
  \usepackage{environ}
  \NewEnviron{hide}{}
  \let\proof\hide
  \let\endproof\endhide
\else %show
  \usepackage{environ}
  \NewEnviron{hide}{\fbox{\parbox{\textwidth}{\BODY}}}
\fi
%

%Then enclose text inside
\begin{hide}
…
\end{hide}

Write inline text in verbatim mode

\texttt{text}

\[\\[0.4in]\]

Table of contents (TOC)

Set TOC depth

\setcounter{tocdepth}{2}

Create TOC without section-numbering

\setcounter{secnumdepth}{0}

set TOC skips

\setlength{\cftbeforetoctitleskip}{35pt} % TOC: Table of Contents
\setlength{\cftaftertoctitleskip}{-.5ex}
\setlength{\cftbeforeloftitleskip}{35pt} % LOF: Listing of Figures
\setlength{\cftbeforelottitleskip}{35pt} % LOT: Listing of Tables

make spaced TOC

\usepackage{tocloft}

\[\\[0.4in]\]

Defining / redefining functions

Define aliases for functions

% copy the definition of \mathbb into \bb. \bb will not change 
% even if you change \mathbb definition
\let\bb\mathbb   

% insert \mathbb wherever you use \bb; more akin to an alias. 
% \bb will change with any changes to \mathbb
\newcommand{\bb}{\mathbb}

\[\\[0.4in]\]

Sectioning

Change section heading style

\usepackage{titlesec}
\titleformat*{\section}{\normalsize\bfseries}
\titleformat*{\subsection}{\normalsize\bfseries}
\titlespacing{\section}{0pt}{\parskip}{2mm}
\titlespacing{\subsection}{0pt}{\parskip}{-\parskip}
\titlespacing{\subsubsection}{0pt}{\parskip}{-\parskip}

Set this option for memoir package to change section heading size

\setsecheadstyle{\normalsize\bfseries}

To define levels up to depth 100 after \subsubsection

\makeatletter
\newcommand\level[1]{%
  \ifcase#1\relax\expandafter\chapter\or
    \expandafter\section\or
    \expandafter\subsection\or
    \expandafter\subsubsection\else
    \def\next{\@level{#1}}\expandafter\next
  \fi}
\newcommand{\@level}[1]{%
  \@startsection{level#1}
    {#1}
    {\z@}%
    {-3.25ex\@plus -1ex \@minus -.2ex}%
    {1.5ex \@plus .2ex}%
    {\normalfont\normalsize\bfseries}}

\newcounter{level4}[subsubsection]
\@namedef{thelevel4}{\thesubsubsection.\arabic{level4}}
\@namedef{level4mark}#1{}
\count@=4
\loop\ifnum\count@<100
  \begingroup\edef\x{\endgroup
    \noexpand\newcounter{level\number\numexpr\count@+1\relax}[level\number\count@]
    \noexpand\@namedef{thelevel\number\numexpr\count@+1\relax}{%
      \noexpand\@nameuse{thelevel\number\count@}.\noexpand\arabic{level\number\numexpr\count@+1\relax}}
    \noexpand\@namedef{level\number\numexpr\count@+1\relax mark}####1{}}
  \x
  \advance\count@\@ne
\repeat
\makeatother
\setcounter{secnumdepth}{100}

Avoid printing “Abstract” when using begin{abstract}

\renewcommand{\abstractname}{}

\[\\[0.4in]\]

Referencing

Allow hyper-referencing

\PassOptionsToPackage{hyphens}{url}\usepackage[hidelinks]{hyperref}  
%hidelinks to suppress red box around links. 
%hyphens option to allow linebreaks in url.

\hypersetup{
    colorlinks,
    citecolor=black,
    filecolor=black,
    linkcolor=black,
    urlcolor=black
}

% for hyper to work properly define page break this way
\newcommand{\sectionbreak}{\clearpage\phantomsection}

\[\\[0.4in]\]

Figures

Move a figure to left

\hspace*{-2cm}\begin{tabular}....

Wrap text around figure

\usepackage{wrapfig}
\begin{wrapfigure}[lineheight]{position}{width}
..
\enf{wrapfigure}

Plot side-by-side figures with common caption

\usepackage{subcaption}
\begin{figure}
\begin{subfigure}
..
\end{subfigure}
\begin{subfigure}
..
\end{subfigure}
\caption{}
\end{figure}

Trim an image

\includegraphics[width=\textwidth,trim=0in 2in 3in 4in, clip]{image.jpg}  
% trims 0in from left, 2in from bottom, 3in from right, 4in from top.

\[\\[0.4in]\]

Tables

Resize a table

\scalebox{0.7}{
\begin{tabular}
…
\end{tabular}
}

Color one cell of a table

\cellcolor
\newcommand{\ccol}{\cellcolor}   % define smaller name

Get a dot instead of colon in table and figure captions

\usepackage[labelsep=period]{caption}

To center fixed-width arrays (m) in tabular

\usepackage{array}
\begin{tabular}{ >{\centering\arraybackslash}m{2cm} | >{\centering\arraybackslash}m{4cm} }

Break a table across pages

\usepackage{longtable}
\begin{longtable}{lll}
…
\end{longtable}

\[\\[0.4in]\]

Mathematics mode

Redefine theorem / lemma environment

\newtheorem{theorem}{Theorem}
\newtheorem{lemma}{Lemma}

For derivatives and partial derivatives

\usepackage{physics}   
\dv{y}{x}  %for derivatives  
\pdv{y}{x1}  %for partial derivatives

Allow breaks in inline math mode

$ bla bla bla \allowbreak bla bla bla $

Allow pagebreak in long equation arrays

\allowdisplaybreaks

Do not break line within mathmode

Enclose expression within {}, e.g. ${a+b+c=2}$.

Background shade of a block of text

\usepackage{mdframed}  
\begin{mdframed}[backgroundcolor=blue!20] 
... 
\end{mdframed}

Adjust width of any text/math block

\usepackage{changepage}  
\begin{adjustwidth}{-2cm}{}
…
\end{adjustwidth}

Cross out an expression

\usepackage{cancel} 
\cancel{x^2}
\cancelto{0}{x^2}

Spacing in math mode

% various degree of spacing from minimum to maximum
f(x) = x\! + 2 
f(x) = x + 2 
f(x) = x\, + 2 
f(x) = x\: + 2 
f(x) = x\; + 2 
f(x) = x\ + 2 
f(x) = x\quad + 2 
f(x) = x\qquad + 2

% set spacing to half of the default value. Just add this line anywhere.
\thickmuskip=0.5\thickmuskip

\[\\[0.4in]\]

Citations

Show citations as numbers inside parentheses

library[numbers]{natbib}

Show citations as numbers arranged in order of appearance in manuscript

library[sort&compress,numbers]{natbib}
\bibliographystyle{unsrtnat}

\[\\[0.4in]\]

Commandline utilities

Count of words in a LaTeX file

texcount file.tex

Latex to HTML

htlatex mydocument.tex

LaTeX to word

# using pandoc (not perfect)
pandoc —mathjax —mathml file.tex -f latex -t docx -o file.docx

Convert latex equation to word equation (Source)

Create an html file using the following script, including latex equations. Then open it in browser. Right click on an equation, select “Show math as”-> “MathML code”, copy the mathml code. Go to word, insert new equation, paste the mathml code as text (Cmd+ctrl+v). The equation will show.

<!DOCTYPE html>
<html>
<head>
    <script type="text/javascript" src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
    <title>tex texample</title>
</head>
<body>
    $$ a = b $$
</body>
</html>

\[\\[1in]\]

\[\\[1in]\]