Playing heads-up is really not the same as playing a normal tournament or ring games. When playing heads-up you have to be very loose and aggressive. When playing a tournament or ring game you should play 20% of all dealt hands. That means you have to fold about 80%. When playing heads-up I fold about 5-10% I guess. I fold hands like , and some more crap. If you got any ace or king you're ahead most of the times. The basic rule of NL texas hold'em is to fold or raise pre-flop. And you should almost always do that when playing heads-up too. When folding to many hands pre-flop you will be eaten by the blinds. So you have to raise almost any hand pre-flop to steel the blinds.

When playing heads-up its much more likely that your opponent will get reads on you. In a ring game your opponent have to focus on 9 (or 6) players. But when heads-up your opponent has all attention on you. So its important to show as less information as possible. So I recommend to raise the same amount all the time. For example: Raising 3 BB's pre-flop or C-betting 50% all the time.

Playing heads-up is really fun when your good at it. There is much more action, pressure and speed than a table of nine players. When playing heads-up you have to win about 60-70% of the games you play. Because for example your risking $10 but you can only win $18 (minus the fee). So if you have lost 1 game and won 1 game you have actually lost some money (in this example $2).

Did you know that most players automatically raise more then usually when bluffing?

Good luck at the tables!