Three things
Here are 3
Pick one. Each takes about as long as it says.
Take one regular journey off the car
Not driving less in general. One specific trip you make every week, done another way, permanently.
Half an hourFreeThe planet
Ask whether it can be repaired, before you buy it
One question at the point of purchase decides the next ten years of that object.
5 minutesFreeThe planet
Find out what your council actually recycles
Ten minutes on their website. Most people are wrong about at least three things, in both directions.
5 minutesFreeThe planet