Ace high is a strong hand.
A pair is a monster.
Always call from the SB, the odds
dictate that you must. Never fold unless its to a raise.
Try to induce bluffs by being weak.
You must slow play monster hands. This could include top pair if the circumstances allow it.
Observe their patterns.
When their stack size is 10:1 compared to yours, put them all in with any two cards.
Bully people by coming over the top of raises if you think they are bluffing.
And lastly, if you lose don't be too hard on yourself. Heads up is very hard, its probably the hardest bit because it is a lottery it can be like playing blackjack
with a few more decisions.