Greg Landweber has added auto completion to the TeXShop editor. Typing a double quote will produce a pair of double quotes with the cursor positioned between them. Typing the ^ symbol will produce ^{ } with the cursor positioned between the brackets. Etc. Thirty-nine such completions are currently available.

Auto completion can be turned off or on with a preference item. The default preference is off. To try auto completion, turn it on.

Auto completion is user configurable. To configure, open the file ~/Library/TeXShop/Keyboard/autocompletion.plist with TeXShop. Read the comments at the top, edit appropriately to redefine Landweber's choices or add your own, and save. Be sure to edit and save in UTF-8 format if you use Unicode characters.

Basic Help
Auto Completion