LaTeX VERY compact itemize

To change these settings globally

\usepackage{enumitem}
\setitemize{noitemsep,topsep=0pt,parsep=0pt,partopsep=0pt}

(And you can use the \setenumerate, \setdescription or \setlist commands for other types of lists)

Or for just a single list

\usepackage{enumitem}
...
\begin{itemize}[noitemsep,topsep=0pt,parsep=0pt,partopsep=0pt]
\item item 1
\item item 2
\item item 3
\end{itemize}