Quote Originally Posted by Minde
Since I would like to learn how to type people by myself, can you all tell me how you're reaching your conclusions?
Right, here's my take on it.

R:

Quote Originally Posted by Minde
The first person (we'll call her “R”) is one of my closest friends. She's detail oriented and loves to have structure around her. As she puts it, give a direction and a goal and put down some solid guidelines and she'll take the project and work to make it happen. She doesn't care as much as I do about the “why” of something as long as she knows the “what” and “when” and such.
All of that suggests a sensor rather than intuitive, and to make a project happen suggests , so that's why some said ESTj, I think. ENTjs would not say "give me a direction and a goal".

However:

Quote Originally Posted by Minde
I've also found her to be very accurate when analyzing people, their character, motives, and how to deal with them. She'll observe things that I completely miss. She is not a party animal and too much social interaction with too many people tires her. Like me, she likes calm, familiar surroundings. With her friends she can be bubbly and giggly, much more so than me.
The above suggests a feeler, more especifically than , especially if you are INFj yourself (and therefore ). The "not a party anymal" etc is a bit ambiguous but altogether she seems ESFj so far, but not very clearly.

But then you said - -

A little bit more about R: Whenever she makes something it's always practical and geared toward usability as opposed to aesthetics. Practicality before beauty
.

This would speak a little bit against ESFj and for ESTj, but not that much, ESFjs can also be practical.

She does like symphonies, sunsets, and such, but I've noticed that it has to be stronger in intensity for her to notice it as something good. She's more likely to aspire to those things, though, than some other people. For example, recently she's been (gently) pushing for a group of us to go hear Mozart.
The way you phrase it suggests as hidden agenda rather than as a strong function, which fits both ESFj and ESTj.

She avoids conflict and will back away rather than stand up for herself. She does not get angry with people, only hurt, I think, though she does not show it a lot. When I see her getting pushed down or away, for whatever reason, I get upset and angry at whoever is doing it. But when we talk about it, she'll tell me why they're doing it (hurt, insecurity, immaturity, selfishness, misunderstanding, etc.) and remind me to forgive them. She is incredibly mature for her age. She interacts best with people who are older or much younger than herself. She has deep insights into human nature
That tips the balance towards ESFj, clearly so IMO.

When she and I are facing a problem, I can solve it (or part of it) in my head and she's the one who takes decisive action
.

I gave her information, she decided what it was about and what to do. On the other hand, she is very receptive to my suggestions and will follow my directions. She doesn't always understand where I'm coming from, but she trusts me.
That doesn't sound at all like an ESTj-INFj interaction, an ESTj would not act as "information receiver" of an INFj. So ESFj; what you're doing is providing her with your strong and (relatively) more active . And you both have a relationship of Illusion rather than Duality.

So ESFj fits best, in fact, even if you were not INFj.