I really don't think there's an answer to this question. If you don't like the aesthetics of the standard bullet point, it's easy to change it using the enumitem package and an appropriate font.
Of course 'childish' is a very subjective notion, and saying that the standard bullet looks like that seems a bit of a stretch. For comparison, here are some suggestions of varying professionalism. If you find squares more professional you could go with the third version.
%!TEX TS-program = xelatex
\documentclass[12pt]{article}
\usepackage{fontspec}
\setmainfont{Linux Libertine O}
\newfontfamily\tombat{Tombats Four} % from http://www.fontspace.com/divide-by-zero/tombats-four
\usepackage{enumitem}
\usepackage{multicol}
\begin{document}
\begin{multicols}{3}
\begin{itemize}[label={\tombat g},nosep]
\item First item
\item Second item
\item Third item
\end{itemize}
\begin{itemize}[label={\tombat X},nosep]
\item First item
\item Second item
\item Third item
\end{itemize}
\begin{itemize}[label={\small\raisebox{.1em}{■}}, nosep]
\item First item
\item Second item
\item Third item
\end{itemize}
\end{multicols}
\end{document}

:)Little I can say about the symbols used for such representations, so my suggestion is to useenumitemand patch your lists to use a better symbol.:)– Paulo Cereda Mar 10 '16 at 16:41