Go easy on the paper kitchen towels. Look for brands that have half sheet option. They do the same job as well that a full sheet does.
Say no to plastic/paper bags at grocery stores. Buy a pair of big reusable tote bags at Costco for just $1.50. Whole food donates a nickel to your choice of charity every time you say no to plastic/paper bag.
Carry your own coffee mug when you go to Starbuck or Peets. They even reduce 10 cents off your bill for your green gesture