… and that I use a lot!

Simplify page and margin size

  \usepackage[margin=1.25in]{geometry}

1.5 or double spacing

  \usepackage[onehalfspacing]{setspace}
       %\doublespacing

Tabular cell vertical spacing

      \renewcommand{\arraystretch}{1.25}

Change list item separation

       \itemsep 1ex

Change spacing around equations

      \setlength{\abovedisplayskip}{4pt}
      \setlength{\belowdisplayskip}{4pt}

Spacing between bibliography items

      \setlength{\bibsep}{0pt}

Nice customizable bibliography style by Shiro Takeda

    \usepackage[authoryear]{natbib}
    \bibliographystyle{econ}

Quick columns environment snippet

    \begin{columns}[t]
      \column{.5\textwidth}
        blah
      \column{.5\textwidth}
        bleh
    \end{columns}

Formatting beamer slides tips from Paul Goldsmith-Pinkham

Generate a list of table and figures with corresponding latex file line number for replication packages