Why?
There are many benefits of living by this rule.
It saves energy, therefore, reduces carbon emission of creating new products. It reduces waste which is good for us (less pollution) but also for wildlife. And it conserves natural resources.
How?
Follow the following three rules.
Reduce: minimise the amount of waste we create.
Reuse: use items more than once and avoid buying single-use items.
Recycle: put a product to a new use instead of throwing it away.