-Don't get married to your big hands postflop - if you get a quarter of your stack in with QQ and someone is showing a lot of aggression on a board with a king, ace, and flush/draw you can still have 3/4 of your stack just folding
-Pay attention to stack sizes - around 10bb you should be in push/fold mode, and can look up some charts to work on this part. Short stack plays a lot differently than deep stack. Similarly, someone with 100bbs 3betting is usually scarier than someone with 10bb 3bet shoving. Also, and this on seemed more obvious but I see this a lot still, a 100bb shove is Way different than a 10bb shove - people shoving with ATo in the first stages of a tournament are donking, people shoving with ATo towards the end might be hoping for a call.
-Play tight in the beginning, and steal blinds towards the end. In the beginning of the tournament, there's no antes (usually) - why throw away 2.5bb or whatever raising king rag on the button to steal 1.5bb? Towards the end of the tournament, there can be 2 or more bb in the middle - if you have 11bb and everyone in short, a min-ish raise on the button with Q8o can make sense; you even have OK
equity if you're called.
-and last - don't care about bubbling! this sounds weird, but if you're just focused on cashing, you'll never make money. unless it's important that you cash in That particular tournament for some reason (say, if you finally get to play in the
wsop main event like you've fantazised about all your life, not that I've thought about it or anything), the bubble is just a part of the tournament where everybody plays reall tight (which you can exploit by loosening up). You're not playing to get your buyin back; you're playing for first!
Good luck!