This is a GREAT thread.
When I was in college, while hurrying to class, I handed a homeless man a doughnut - and as I kept walking I then worried about its lack of nutritional content. However, I consider it to have been a generous thing on my part, young as I was - this might sound really odd, but it was my breakfast and I am 5'9" and was no more than 110 lbs at the time. I kept my coffee and was hungry till lunch.
I went to school in a pretty big city. There were food trucks, I would get sandwiches on weekends when the dining halls were closed, and if there was anyone homeless or hungry on the street I would add to my order a hamburger with everything (meaning lettuce tomato etc and more nutritious than a donut!) and hand it off. It was less than 5 dollars each time and I could fold it into my own food budget without going hungry (as in the doughnut situation - it's a true story but a little jokey. I did not suffer true hunger.) There was no danger to speak of; it was such a heavily populated area and there were always lots of other people in sight.
This reminds me of a thread elsewhere on how to get along with others... I forget who, but I noticed someone said they smiled and chatted to people - I do the same thing! Some people don't care to interact, but some are pleasantly surprised. I have always loved taking trains and subways and either chatting or, if others didn't want to be disturbed, simple people-watching. (Subway commute was also a good way to learn balance - stand on one foot, reading a book with one hand and, if you can't even get a grip anywhere with your other hand, you use it to balance your weight so you don't get slammed as much into the people standing next to you. It is what I imagine surfing would be like.)
I consider myself to be fairly street smart. No one is 100% safe 100% of the time, but I was raised to understand certain things to take care of myself - the most basic being, "don't stare up at the tall buildings!" and adding things like "If you're lost, don't stop - keep walking till you figure it out."
Once, another goofy-but-true story, I was walking around a big block between a couple of huge skyscrapers, and I knew no one else was on the street.... but I kept hearing a tiny jingling behind me. Rather than turn around, I circled the block before I realized my pocket had a little hole in it and there was some change clanking in there. But that was me acting on my city-instincts/learnings - I was NOT going to stop on a street with the chance of only one other person in sight.
More recently, the suburb I now live in... Well, I don't get out much at all, but in the winters there has been a particular homeless veteran out by a stoplight I'm at on a fairly regular basis.. I keep granola bars in my car, theoretically for myself but now I make sure I have extra if I see "my" guy there - he's smart and kind and grateful for food and also grateful for a smile.
This is when I find contempt for other people - I have seen people in other cars staring at me in disapproval. This is inexcusable. They don't OWE anyone anything, but I don't know why they begrudge such a small kindness - it's not like I stop traffic; I give him food if I have it and happen to be stopped at the intersection. Maybe they think I am giving him money and not food? I do agree, I'm not into handing out money. When I have had my own budget, I would donate money to places that could distribute it safely and efficiently. These other things are small kindnesses. You can look people in the eye.
The first time I gave this local, hungry man some food, I called him "sir" and he said "aw don't call me sir I was just a sergeant" and I think that was so sweet. That's why I think of him as "my guy". Sometimes I see him and I don't have anything; I'm sure he sees me. I can only hope he is helped in other ways by other people. You can't save everybody but you can make life more pleasant in some very small ways.
I do realize that there are lots and lots of places and circumstances where it would be unsafe to do what I mention here. I would also not begrudge someone who volunteered time instead of money, or if someone was too depressed anxious or otherwise unwell. I would love to volunteer my time, but I do not currently do so because I cannot adhere to a schedule, due to my illness. It is the first thing I would like to do when I am healthier.
I don't think anyone is obligated to do more than acknowledge that people are people and should not be regarded with contempt because of how they look.
Treating people with simple human decency is a gift in itself. I know, again, it is not always safe to do things like make eye contact. While in college - I lived in less nice neighborhoods where it would have been dangerous to stop and even acknowledge anyone. In Brooklyn I lived for a while across a handball court and it was sketchy! That is when you pretend not to see ANYONE. But when I was at a subway stop or with multiple other people, I enjoyed smiling and saying hello. Some looked like I was insane, but some people appreciated the friendliness!
None of these are brags or suggestions for what other people do - they are free associations that came to mind after reading through this really cool thread. Everyone here is really very kind in such a wide variety of ways! Please forgive my ramblings. I've enjoyed thinking back, reminiscing on all this, when my life is currently almost empty. :)