Grow, raise. harvest, and/or produce your own food supply.
Harvest seeds (and critters if you consume meat) from nature to do the above.
Go everywhere on foot - unless you can provide a mechanical method of transportation that doesn't require the purchase of any material or a fuel source that cannot be produced by you alone.
Raise cotton or sheep (or similar) to produce fiber to spin into thread, to make into fabric to create your own clothing.
Grow and harvest lumber (or other material) to build your own shelter, again, seeded from nature, not a catalog, internet or store.
Anyone not doing all of the above, just to name a few, is contributing to the problem of greed as it's being defined and presented by junebug and Heirophant.
See how foolish this can get? Are you both hypocrites? I'm assuming you don't already do all the above, am I right?