I taught a 4-day workshop one time where a third of the participants were dominant Fe's and I'd venture to say all mature people--a perfect fish bowl of what Fe looks like at its best. In subtle ways they were constantly making sure everyone was having as much fun as they were, making sure the coffee stayed fresh and hot, suggesting a bit better arrangement for tables so everyone could see, organizing lunch so no one who wanted to be included was excluded, etc. The whole room was happy all week.
Fe at its best is working toward harmony (not manipulation), recognizing others' needs and acting to meet them when appropriate (not codependency), ensuring a group remains true to its cause (without becoming bossy), and listening and responding (sincerely). Those are the behaviors you see when Fe is making decisions based on stepping into the shoes of others and understanding the impact on each person of various alternatives. Like all types, they're great people when they have mature command of their function and a well-developed auxiliary to keep them grounded...
Fe is my auxiliary. It's never as natural for me to read a room (unless I'm training and then it's my job and the instinct kicks in), note others' needs, speak up with compliments, etc. It always feels like an afterthought. Here's where I have trouble, though, with the 8-function model as I'm not sure Fe is a "thing" as much as "I'm an Introvert who prefers Feeling but has to give myself a jump-start to get out of my Introverted world and act on what the Feeling function just decided..." That delay probably lessens the sincerity meter with others since my reactions are often delayed.