Byrons_Ghost said:One thing to consider about this is the character's motivations for acting the way he does. Even though the movie presented this as a philosophy, each of the characters which lived this way had definite, concrete reasons for doing so. For the Chinese magician, it was part of his act- he was constantly supporting the one trick for which he was famous. And the two main characters both had personal and family reasons for keeping their secrets hidden.
The skills etc listed above are good starting points. The next question should be what it is that your character needs to hide from those around him, and that should give a fairly good idea of how he needs to act and what tricks he needs to pull.
Actually, Whiz can probably explain it better than I, but as he explained to me (I'm his DM) this guy comes from a culture of gnome's who are basically "Orthodox- Glittergold Illusionists" Gnomes who just hide their city behind illusions to avoid invasion and then live life as normal? AMATEURS. The entire culture keeps up a certain image to portray helplessness and make them appear non-threatening... and they're very very not.