Aristophanes, Plutus 410 ff (trans. O'Neill) (Greek comedy C5th to 4th B.C.) :"Ask Hekate whether it is better to be rich or starving; she will tell you that the rich send her a meal every month [i.e. food placed inside her door-front shrines] and that the poor make it disappear before it is even served."
In ancient Greece, altars to Hecate were set up near the front door of homes to protect the house from being entered by unwanted entities and energies, as she is a guardian of boundaries. Each month, on the darkest night, the night before the new moon, a supper was placed on her altar as an offering. More often than not, destitute humans would eat the supper before the night was out.
This is a wonderful tradition to modernize and carry into our everyday lives, but it can be problematic, as the world has changed. First, not everyone wishes to make their Paganism public, so a shrine on the front porch probably isn't in the cards. Having homeless people remove things from your porch may also not be feasible or desirable. When I lived in the city there was a homeless man who picked up our empty cans from our porch to turn them in for the deposit, most of our street participated; but in our current neighborhood, someone's likely to call the cops if they notice someone taking something from our porch. If I were still in that neighborhood, I might add a little something extra once a month to his pop can pickups in honor of Hecate.
In later times, offerings were left for Hecate at crossroads (another liminal spot). Here is another option for you. If you are aware of a place where homeless people gather, it might be nice to prepare a meal and deliver it to them at a nearby crossroads. If you do this, bring relatively non-perishable items that are easy to get open (don't require a can opener) and easy to eat out of hand. Some ideas might be canned fruit, puddings, sardines, crackers, breakfast and granola bars, etc.
Many people find homeless people frightening so you are not alone if you are one of them and it's true that many of them have mental illnesses and addictions that may make them dangerous, but they can also be great to get to know. I have more than once told a panhandler that no, I didn't have any cash, but I did have a credit card and I would be happy to share a meal with them in a nearby restaurant in exchange for some conversation and gotten a wonderful afternoon out of it. (A few called me unflattering names and declined.) However, on several of these occasions it did become difficult to extricate myself from the situation once my available time had passed, necessitating some sneaky maneuvers to make my escape.
It is thus often safer to do your offerings through an organization. You may choose to make your monthly offering of food to a food bank instead and this is perfectly acceptable. Or, you may choose to do an offering of self and volunteer at a soup kitchen. Or you may choose something completely different. Interestingly, many social services organizations call themselves "Crossroads", so it may be easier than you think to leave an offering at the Crossroads, if you're not too literal.
Whatever you choose to do, be sure to involve the kids! They can help by picking out the food for Hecate's supper on shopping trips, packaging it up or, depending on their age, they too can volunteer!
I'd be interested to hear what folks do for Hecate's supper. Please let me know in the comments! Myself, I am going to do something different each month and blog about it. Stay tuned!