Ride bikes or walk to commute when you can.
Make a shift in your diet to include less meat, more organic vegetarian meals.
Use a rain barrel for watering.
Instead of hours of TV to try to relax, take an hour for a yoga, meditation, or yoga nidra practice.
Better insulate your home.
Shop at a thrift store and buy used whenever possible.
Grow a food garden.
Allow your hair to dry naturally.
Do not buy single use beverages.
Please comment if you have any other ideas!