One thing I noticed that I do that helps keep my opponents guessing is change my playstyle constantly. Sometimes between games, sometimes within the same game, sometimes within the same stock. If the opponent is used to one playstyle, then gets faced with another, he may be caught off-guard.
Obviously, I try to be random with my playstyle, since if I am predictable in any way, I can easily be punished.
Just some advice to people who are affraid to be aggressive against good people... just change it up from time to time, you never know how good or bad it can be unless you try
That said, no matter how you play, play safe. ... I mean, play smart