What characterizes you IRL? How do you behave in social situations/educational situations/family gatherings/where will i find you/where will i never find you/how much do you share about your personal lives, etc.
Please help me figure out how to spot them more.
I really don't think there's a pattern to it; if anything, being on this board has shown me how varied INFJ's can be, in terms of jobs, values, interests...and a lot might also depend on the INFJ's own personal life experiences, how they've integrated those things into their life, and how they then adjust and perceive the world around them. For example, in high school, I was a loner. But one of my INFJ friends was quite opposite - in fact she was well-liked. We were just at different..stages...or it had to do with our upbringing....or a lot of stuff *outside* of mbti!!
In social settings, I think you could easily see one INFJ react to it in a much different manner from another INFJ -- so whereas one might decide not to be terribly talkative, and will be quiet, another might be in 'On' mode that night and might appear extremely extroverted. I'd be really hesitant to pinpoint traits that all INFJ's will display in social situations. It often depends on context. I would say INFJ's tend to be quiet and in the background in large groups, and aren't really at ease in them, but I have one INFJ friend who counters this, as she can be extremely talkative (because of how she was raised, she learned those skills) to strangers, MUCH more so than I. But it depends on the context for her.
In general, most everything about the INFJ will stay inside the INFJ for a while, until trust is built. But I don't really see how this would be evident to the outsider, other than you might sense the INFJ is being cautious or deliberate in what they say, and how they say it, or you might sense there are a lot of layers. You might sense a lot more is being unsaid than said, but again, I wouldn't know. ;-) For me personally, it all depends on how I 'connect' with the other person, and what I sense the other persons' motivations are in wanting to know me - bottom line, if I don't trust the persons' sincerity and genuineness and openness, I'm not going to be open to them. I'll play it very safe and keep things very factual. Nothing deeper, nothing explanatory. To be completely honest, there are certain people I just instantaneously 'click with/connect with' (meaning I don't have to put forth much effort in the interaction, and we just feed off of each others sentences and it's very fluid) and they're always NF's.
-- so with people I just immediately connect with and feel we're speaking on the same wavelength, I'll be much more inclined to be open myself. But that happens rarely. So with everyone else, it's a very slow process.
The 'where will I find you'/'where will I never find you' thing can't be used with INFJ's I don't think. [actually wouldn't this be the same for ALL personality types? It's dependent on interests?] It depends on the particular INFJ's interests and values - it's not across the board.
For example, one of my good INFJ friends is a Christian. You'll find her at Bible studies and church. But in addition she's very passionate about environmental stewardship, and her work and much of her volunteering is related to that. You'll also find her out hiking, or taking spanish classes. And you might find her in Kenya or Costa Rica. ;-P
Another INFJ friend you'll NEVER find at church, because she's very much not into that. You'll find her in running clubs, or in coffee shops, or at book clubs, or at yoga classes. Prior to this, when she was in college, you would have found her in electrical engineering courses and she would have been in Goth attire and she would have been at the clubs, dancing a lot; but she's no longer into that. Prior to that, she was raised Jehovah's witness, so she would have been part of that circle.
A male INFJ coworker...I don't know where you'd find him, because he's really introverted and he's not really interested in any club-type activity. He has his S.O., and likes to travel, but outside of that, you're not going to 'find' him anywhere.
And myself...I've written about myself all over the boards. ;-) I direct you to those threads.