Are there other tools used by the feds to increase money supply?

The Federal Reserve (or Fed) increases the money supply by buying back outstanding U.S. Gov't Securities (bonds and such). By doing so, they are adding more currency into the economy, thus increasing the supply of money, or money supply.

Conversely, the Fed can also lower the money supply. To do so, they simply sell U.S. Gov't Securities. This means that they sell bonds out and bring currency in, thus reducing the money supply.