That’s a really good question. Part of the problem, of course, is that the game is rigged: consider how difficult it is to buy food that doesn’t feed the Nestle war chest.
As a society, I think there are moves in the right direction - I just stumbled across something called Community Wealth Building, which is very cool, for example.
But as a private individual? That’s harder. I’d love it if there were an Amazon equivalent out there that sourced exclusively from worker owned co-ops, or at least unionized businesses, but as it is, I’m coming up dry…