What are the keys to HU NL?

[Vannek]

This one area I'm currently working on. Online I'm having
trouble with 'outplaying' them once it gets HU.
Its tough to know what their holding so they only thing I can 'read' is the bet size, which can be tricky with some players with weak bets meaning strong or vice-versa(but I'm my experience the strong bet means weak, as the guy is anxious to win so he bets big praying to you fold), so I'm focusing on making standard bets so I dont give any information
But I would like to know from experienced sng players what are they systems once it gets one on one.
I current try to semi-bluff on draws and when I get bad hole cards I generally try to steal to keep him on pressure, then if I he calls and I have a good stack I fire an second barrel again to not let feel confortable any minute, any advice?