LaTeX: Reduce line spacing in enumerate environment

To change enumerate, you must install package enumitem

\usepackage{enumitem}

to change enumerate globally:

\setlist[enumerate]{itemsep=0mm}

 to change enumerate locally,

\begin{enumerate}[itemsep=3mm]

 for example:

\documentclass{article}
\usepackage{lipsum}

\usepackage{enumitem}
\setlist[enumerate]{itemsep=-5mm}

\begin{document}

\lipsum[1]
\begin{enumerate}
    \item one
    \item two
\end{enumerate}

\lipsum[2]
\begin{enumerate}[itemsep=5mm]
    \item one
    \item two
\end{enumerate}
\end{document}