Control + D Will save you a lot of typing!

command + d.  starts selecting next thing same as highlighted

option: creates multiple cursors

Easy Lorum Ispon

Just type in Lorum and hit tab and you'll get a snippet of Lorum Ipson, like so:

Lorem

Emmet

This allows you to quickly write HTML if you want to create a main section, type main then a tab.  If you want to create a new section, type section.class-name and hit tab.  Emmet will create the element with the tab, saving you hundreds of hours worth of development effort!