Change your travel behaviour, think more in terms of public transportation, if possible, walk or ride your bicycle instead of taking the car
Reduce your house heat by 1C, keep the windows closed while heating, dress warmly
Choose products that come with lightweight packaging
Turn off lights and appliances when you are not using them, use energy-saving light bulbs
Reuse plastic bags for shopping and storage
Use a microwave instead of a stove to reheat food
Use rechargeable batteries instead of disposable batteries