The worst thing you could do is give them something as that implies they can stay.
I made that mistake once at the parking garage close to my office.
Before I knew it they would be there every week and soon every day.
I tossed them a few coins from time to time but I don't carry cash with me often.
At some point I got sick of it and their increasingly agressive tone and said: "Sorry I'm in a rush" only to very slowly and very visibly pay my parking fees,
move to my car, linger about, make a few calls, drive a few rounds around the parking lot and then leave. While they gave me the finger

Anyhow these people should become actors, I later discovered the homeless shelter and drug den were like a few blocks away from the parking garage.
They were basically collecting cash in shifts from travelers who thought they slept outside in the cold.
There's one famous homeless dude in the area that does get money from everyone. He's drunk AF and lingers around the station but he always puts down his bottle on ramps, sign posts, car mirrors and other surfaces.
For some reason it stays perfectly balanced. I think he's a Jedi of sorts, he puts his bottle down on like a bowl shaped garbage container and then he points at it and says: "Stay there my friend" and walks across the street.
Everyone is fixated on the bottle that is wobbling a bit and yet it doesn't fall on the ground. He collects some cash and food and then returns to his bottle. "Thank you my friend" he can do it with basically any bottle he's carrying
