Moving away from packaging things that don't need packing would be a good start. One of the grocery stores I shop at moved a lot of the smaller bulk produce it

Moving away from packaging things that don't need packing would be a good start. One of the grocery stores I shop at moved a lot of the smaller bulk produce items into shrink wrapped packages in poly-styrene trays. Consumers can also stop buying pre-peeled fruit and vegetables (corn on the cob, oranges, melon, etc).