ctrl+shift+R refreshes the intellisense cache. There is also a button you can add to the menubar to do this.
when you expand a table name in the object explorer, just dragging the word columns to the query screen will put a list of all the columns in the table into the query.
Ctrl + L – Display query execution plan
Ctrl-K,C to comment out the selected text and then Ctrl-K,U to uncomment.