Play a LOT of hands - Chris Ferguson says he plays about 70-80% of the hands in a heads up situation. While I'd certainly advocate playing any Ace, or any King, Chris says he plays down to any Jack.
Apply Pressure - raise preflop with any hand that has a positive expectation, and any hand that has an Ace or King. Raise with any resonable holding if you are in the small blind (since you will have position for the rest of the hand).

If the flop hits you, there is already a larger pot to be won. If the flop doesn't hit, you are in a position to pick up the pot with an additional bet because you've already represented a strong hand.