There is no first impression I’d like to give everyone. For most people I’m good with “seems decent enough,” but there are people I’d be quite happy to think me a lunatic. I guess the most useful first impression would be to be seen as one who can spot someone who is manipulative, a friendship “level jumper,” or of nefarious intent so as to minimize the approach of such people in the first place. [The problem is that most such people see themselves as charismatic and gregarious rather than as manipulative. They don’t realize their stank shows through.]