You should always stay cool and focused,and not let emotions to take over you..I know it is sometimes hard to lose to someone to a lower kicker,but you shouldn't think about revenge in the next hand when you play against that player...You will get your chance,just be patient...
And I would suggest you to play only premium hands at the begining of the tournament because there are almost always players who are playing for thrill so they will follow almost every bet.Once these players are eliminated,real poker starts...