CTRL+D (Might be CMD on Mac) will also select the next occurrence of a symbol/selection. And Ctrl+U will undo a selection from this method or the parent post's method.

Aside from being able to simultaneously write in multiple places, you can copy-paste across multiple cursors; highlight 5 variables, copy, create 5 new lines with cursors, paste. Each line will have one of your copied variables. Try using Find with regex and alt+enter to select all matches with separate cursors.

Many plugins also support or add onto this feature. I love TextPastry to easily insert number ranges and patterns across multiple cursors.