When TeXShop runs for the first time, it creates a folder

  ~/Library/TeXShop/Templates

and places the files Graphics.tex and LatexTemplate.tex (and a folder named "More" of additional files) in this folder. The names of these files are shown under the Templates pull down menu at the top of the input window. Choosing one of these items inserts the contents of the template file at the current cursor position in the source. The Graphics and LaTeX templates were recently revised by Will Robertson to follow modern TeX practices; Robertson provided the templates in the More subdirectory.

Template files are standard TeX files which can be opened and edited by TeXShop. Additional TeX files can be inserted into the Templates folder; they will also appear under the Templates pull down menu provided their names end with the extension ".tex". The original template files can be removed if desired.

To create a hierarchical structure in the Templates menu, place some of the template files in subfolders of ~/Library/TeXShop/Templates.

To restore the original template files, delete the Templates folder and run TeXShop again. It will recreate the folder and restore its original contents.

When users upgrade TeXShop, the templates folder is not updated because the user may have modified it. If an upgrade changes default templates, the new templates will appear in ~/Library/TeXShop/New. Drag those you want into the Templates folder. Changes will be reported in "About This Release" under the Help menu.

The commands \usepackage{amssymb} and \usepackage{graphicx} mentioned earlier are included in recent copies of the LatexTemplate, but not in copies from very old versions of TeXShop.

Basic Help
Modifying the Templates Menu