Hammer hits above:
When swinging the hammer, if facing to the left or right, Link will hold the hammer over his head for a moment before pounding it to the ground. As he swings it down, it can hit enemies that are located above and slightly in front of him. Take advantage of this to hit enemies you'd rather not line up with.

This is especially effective against Deathknights, as they have a tendency to charge towards you. If you line up with one horizontally and get it to charge, move downwards 1 row and time your hammer swing. If you connect, it will drive it back, and you can hit it again. Repeat until the Deathknight is defeated. This trick is even more useful in rooms where you can force the Deathknight to come at you via a 1 tile-wide horizontal pathway that opens into a larger space, such as this:
Code:
*****  *****
*   *  *   *
*   ****   *
*          *
*  L****   *
*   *  *   *
*****  *****
Just stand where the L is and wait for them to come to you. ALTADD has a perfect room for this in it's house of horrors.