Typical packages:
\documentclass[12pt,a4paper]{article}
\usepackage[english]{babel} % Set language as English
\usepackage[utf8]{inputenc} % Tells type of encoding
\usepackage{amsmath} % For a better display of equations
\usepackage{amsfonts} % For an extended set of fonts and symbols for use in mathematics
\usepackage{amssymb}
\usepackage{hyperref} % To make hyper refs
\usepackage{graphicx} % To include pictures
\usepackage[margin=2cm]{geometry} % Sets margin
\usepackage{setspace} % For spacing
