Do it yourself!
Grow your own food or at least some of it. Make your own yogurt, bake your own bread, make/take your own lunch to work, bring your own coffee/tea cup to work and reuse it. Use tupperware instead of disposable plastic sandwich baggies. Compost. Wash dishes by hand. Take 3-minute showers. Collect rainwater in barrels and use it to water your garden.