This waht I do at every job I get. I start out working very hard, at near my capcity, my bosses will then see me as a hard worker (I usually keep this up for 6 months to a year). After I have built a good rep, I determine whether the effort I give is worth the returns I get (pats on the back, raises, promotions, etc...). If it is not, I start slowing down little by little until I get things down to a comfortable, yet still productive, pace. Since I already made a good impression, my bosses will always see me as a hard worker no matter what. If I ever screw up, or if they catch me slacking off, they will make the excuses for me themselves because, in their minds, I'm always going to be a hardworker so the screw up must have been some sort of rare anomaly.