Maybe I can share my own story to aid some people think a little different about this thematic.
Till last month I used to work in a local chain supermarket.
It's smaller than they use to be, so when I was shift supervisor I knew most of our regular customers.
One of them was a homeless guy that you could sometimes see traveling from one town to another with his home packed on a bicycle he was pushing around.
When it was late and I was alone with few of my colleagues he sometimes came in and bought one or two packs of that cheap ready-to-bake breads we had.
One evening I watched him on our parking lot, eating that dry bread he just bought, I went to him and asked if he is ok and maybe needs anything I can help with. He was friendly, but not really talkative and specific on questions. He only told me how struggles to get something warm to eat.
I then bought him a meal and warmed it in the personnel-kitchen, when I went back to him and told him it was for him, his weathered face formed an unbelievable expression of joy. I think that was one of the best moments for both of us.
Though some of my colleagues thought of him as just a dirty, smelling lump, I talked to him any time I saw him and had time to spare. He was one of the most positive guys I ever met, minding his situation. But the times we met, I asked him how he is and if anything concerns him. Eventually I bought him a bag filled with soap, toothbrush and toothpaste, matches and candles. Because thats what he told me would be something he can rarely afford. And though my job didn't paid that much (some of the reasons I finally quit), I imagined how I can at least sleep in a warm bed and eat when I'm hungry, when he cannot.
To have a little money less for oneself doesn't matter, because what that would be worth to you is exponentially much more worth to someone who has nothing.
TL;DR:
Anything that is basic for you, is not basic for everyone. Though food might be the most important, essential stuff like soap or candles for the dark don't harm anyones wallet, but might be like luxus for people that have to save money to even buy a meal.
Help someone out and make their day special with a little gift of casuality.