I was never a 121 guy or anything other than 135 scum/Alaska pilot in general, but I will say that I took my responsibility to my customers extremely seriously. Be a good human. Don't work yourself to death, that's expected by management but absurd and counter productive to safety and took me a long time to learn, but do recognize that people rely on your service and you hold a lot of lives in your hands. Even if you're just flying around a few people in piston singles or whatever, you have an ethical obligation to do right by those people as best as you can. Consequently, that means some times you'll have to disappoint them, but you have an obligation to do your best at whatever you do. We are blue collar workers - each flight is like an potter crafting a vase - yes, not all the vases are perfect, but each time we try to do a little bit better than the last one.
To me, at least, I didn't really care about how I looked, or if I was clean shaven (not that what I was doing really required that), but I did really care about the people I flew. If the elders were getting off the plane in the village, if they needed help, I gave it to them. I tried to learn some of the local language everywhere I went in Alaska, and I tried to connect myself to the communities I serviced. That experience doesn't have to stop just because you're flying 190 tourists to Tampa or whatever, you can still "care" about the people under your charge.
That doesn't mean obnoxious PAs where you talk about servant leadership or other such nonsense. If anything, it means less of that. On the contrary it means that you offer to help people when you think they need help, you try not to inconvenience people, and you have a little heart because the ramifications of your decisions can effect a lot of people. A perfect example of this from my career was after a particularly traumatic medevac, I noticed that the mother of the patient was so alarmed and in shock that she was starting to just wander off onto the ramp somehow past the medcrew (who had suddenly gotten very busy busy and stopped watching her). I stopped putting the airplane to bed, went and got her and physically guided her over to the ambulance while the crew was still working to help her kid, "hey why don't you come with me and get buckled into the ambulance, ok? Oh, yeah, we see this sort of thing all the time, the medcrew I have tonight is fantastic, I see this 10 times a week, you've got nothing to worry about. Watch your head as you sit in here, be sure to connect your seatbelt, are you comfortable? It's going to be ok - are you doing alright? I've got some water here."
Now, the god's honest truth is that I didn't know if the kid was going to be fine - arguably probably not - but my responsibility to my passengers didn't stop until everything was handled, even though I had already been shutdown for 10 minutes or so, I could see that she was in trouble (both in terms of being unmonitored on the ramp at night and wandering around in shock), and I could do something about it. The prop ties and paperwork could wait (even though the wind was howling). So I went and did something about it.
When you see the right thing to do - and believe me, you know it when you see it - just go do it. Literally just care about people enough to try to do the best you can to help people. You're not going to get rewarded for it, hell, you'll probably make things less convenient for yourself a lot of the time you do the right thing - but do the right thing anyway. You owe the people in your charge a little bit of explanation when things are weird, delayed, or chaotic if you have time to give them that information.