I worked in a few bars and hotels in Toronto during the seventies. When someone walked in, I could feel if they were tippers. Any group of guys would take turns buying rounds, but the cheap guys would go the washroom when it was their turn to ante up.
When I got to the table to collect, the men would say, "Hey where's Joe or John?" or whoever. Someone would say that Joe was watering a horse and the other guys would start to dig in their pockets. I would stop them and ask if Joe did this a lot. If there were all nods, I just smiled and said, "I will return!"
When Joe returned, I would walk up to him, tell him what the tab was and wait. The rest of the table would be laughing, sometimes out loud and sometimes stifling the laughter as Joe began turning his pockets out to pay the bill. If Joe didn't tip, the rest of the group hounded him until he reluctantly forked over a tip. I did this quite a few times when I encountered cheapskates. I bet Joe thought no one noticed why he always left.
People who are never generous with money, are rarely generous with anyone at any level. I am not talking about poor students or financially strapped souls. There are also some generous people who have strings attached, so maybe not so generous. Some good hearted people never believe in lending, yet feel guilty when they don't. Someone told them to never lend, it makes enemies out of friends, but depending on what it is, a lack of generosity can make enemies too. Lack of generosity can make enemies out of anyone, never mind if it's money, a second chance, a helping hand or a judgement of some sort...
Going away from the heart really causes problems, short and long run. So stay with the heart. Say no when you feel it in your heart, not your mind - don't get logical. If you know you're going to kick yourself after, don't do it. Don't get taken advantage (and you can always feel that), your heart won't let you, your head will.
I worked as a family support worker for years in Edmonton. Most of my clients were poor and lived in poor areas. There were times I locked myself out of my car, had a flat tire, or had trouble starting my car - help always arrived within minutes. Sometimes a client, but often a stranger would stop and offer help, accept no money, fix my problem and saunter away. I would rather get stuck in a poor area anytime. They were always so polite too. I know that if I had been stuck in a rich area, I would still be waiting!