Try not to over think it and don't deviate from playing solid-strong poker. Remember the most important fundamentals that don't change, but become even more important, like position.
Don't suddenly get into fancy-play mode. The goal should be to capitalize on your opponents mistakes. You don't need to be aimlessly aggressive. One reason to be very aggressive would be if you're opponent is overly passive. Try to always have a reason behind your play, and adjust your play according to how you're opponent is playing. If you have 10 BB's or so though, you can just play nash if you're opponent is decent and you feel that's the biggest edge to be gained.
Also, you need to have super thick skin to play MTT's and just know that a few games means very little and you can't really assign blame, nor have much control over you results HU in such a small sample. That goes for HU in general, let alone tournaments where you're likely short-stacked.