Stores are more than willing to hand out cardboard boxes.
I have quite a collection and have laid them down with grass clippings, wood chips, and shredded up leaves on top of them.
I’ll toss on some manure once the plants go in.
I found some places with decent soil, too and hauled that over and mixed it in with the rest of the stuff.
I’ve got two compost bins going but they are frozen solid right now. It’ll be spring before they thaw out enough to turn and then I’ll have to be diligent to do it a couple times a day. One is almost ready, the other is in the filling it up stage.
I save my egg shells, plus tea bags and coffee grounds all winter in the freezer....my compost pile is also frozen solid...