Are there any specific options that I can enable or disable to improve compiling time ? I don't understand most of what is included in the settings so I can't decide on my own (new LaTeX user here).
For example, I recently learned that adding % !TEX TS-program = pdflatexmk at the start of the document automatically compiles twice to display the PDF. So maybe there are other quirks that I don't know of that can assist compiling speed instead ?.
These are the settings I have in TexShop Editor :



And the documents starts with :
% !TEX TS-program = pdflatexmk
\documentclass[12pt,a4paper]{report}
\usepackage[lmargin=3.81cm,tmargin=2.54cm,rmargin=2.54cm,bmargin=2.52cm]{geometry}
\linespread{1.5}
setspace, though\linespreaddoes have its place. (Can't help with the speed question. As far as I know, pdfTeX is appreciably faster than LuaTeX, and I don't really use XeTeX. You might want to search for questions related to dumping formats; but this is not a beginner topic.) – jon Apr 19 '13 at 05:02