Superficially good looks and good manners, perhaps.

Advice: make sure the impression continues well after your first few hours/days with the person. I seem to have a 0% retention rate for friends. At some point after our first encounter, all seem to decide there's something off about me. Perhaps my mistakes include: using our newfound trust to reveal some true oddities (people seem to distinguish between normal quirks and odd quirks, as strange as that may be, and I ain't even very far into "odd quirk" territory), and not having a proper understanding of how relationships progress – therefore, keeping in touch either too much or not at all.