Reduce
Really, the best thing that we can do for the planet is to use less of it. At the heart of the environmental crisis is our consumer society. Here are a few questions you can ask before you buy: Do I, or the other person I am buying this for, really need this? Is there another product which would do the same thing but more sustainably? Will this last a long time? Do I know how this item was made, how it will be used and how it will be disposed of? Where was this made and under what circumstances? Are the materials used to make this renewable and have they been harvested in a sustainable manner?

Reuse
Regrettably, because we live in a disposable society, we are encouraged to buy a new improved item even if the one we have can be repaired. When we buy, we should buy items which are durable,we should maintain them, and have them repaired when necessary. If we practice this, many things can not only last a lifetime, but can be passed along from generation to generation. If something is truly unusable for its original purpose, try to be creative and think of how else it might be used. When you are done with it, think of whether someone else might be able to use it.

Recycle
Rather than throwing an item out when neither you nor anyone else can make use of it, have it recycled. And while recycling is not perfect it requires energy and the process of changing something into something else often produces by-products it is better than sending goods to the landfill or having them incinerated.
Find out what types of materials can be recycled in your area. Clean and sort the materials before putting them out on the curb often collectors will not pick up recycling that is mixed or contains non-recyclables.

For more tips on how you can make a difference go to:

http://www.greenpeace.ca/e/resource/green/index.php