We've just spend nearly 2 yrs renovating a derelict property. We lived/worked onsite in a caravan so also always there. I started making everyone drinks, but it became multiple times a day and was becoming ridiculous trying to wash mugs all day. It depended on the trade coming in.
Someone there for only a day or 2 I'd make them a cuppa and if I had any, put a few biscuits on the side
We had some trades here for weeks so I set up a station with a kettle, mugs, spoon and a bottle of milk, although mid way through, they brought along their own kettle, coffee and milk. I'd recommend getting sugar cubes, because they are less messy than loose sugar everywhere.
Sometimes we've leave out biscuits, but rarely eaten. 1 guy clearing the garden took the entire unopened packet with him, but that was the only time. I did make bacon rolls one day, and occasionally a fruit slice/cake of some sort- but not daily nor even weekly.
In the heat of summer, I had a cooler box filled with ice and bottle of water and cans of drink they could help themselves to. They all appreciated this.