Building a good reputation. It smart to think about doing this. Think about how you would like to be viewed by others. Think about your career and your dreams then fashion your reputation after that. You want people to remember you, most everybody deep down wants people to like them and say positive things about them. Build a reputation where people do not have a choice but to say good things about you.
Be unpredictable, never let people be able to tell what your next move is.....then people will become bored with you and forget you easily. Every once in a while be creative perform an action that is most definently out of the norm for you, just to keep people guessing. Do not do anything stupid, imoral or against the law. Just do something that grabs peoples attention and makes them say "wow, I have never seen him do anything like that before".
To set yourself apart, you could do a number of different things. Develop a certain way of dressing that seperates you apart from the crowd. It does not have to be anything major or weird. It just has to be something that sets you apart, something little, yet conspicuous. You could also have a little nervous tick that people remember and find endearing. Or perhaps, accentuating one aspect of your personality that you really like.
Once you have built a good reputation, guard it with your life. It is hard to build a solid reputation with people, once you have done so, there is no point in losing it. What kind of reputation do you have?