How can you help in saving this universe

Mankind is self destructive.We are always doing things that harms the earth and causes pain for living objects.The technological advances which we percive to be helpful to us are in a away destroying our earth.How can a common man like me help in preserving nature and promote ecological balance.
This is a list of things,which can help us :
1.Water Conservation - Water is among the scarcest commodities available on earth.Misuse of water and other ecological factors have resulted in causing harm to us.Water can be used in the best way and its optimum use will help in saving our universe.

2.Fuel Conservation - Fuel in the form of petroleum products is the most sought after product.