Following are the things which I have been doing since past few years. I would recommend the following tips to all those who are concerned about environment and about conserving energy.
1) Have a beautiful garden in your house. Beautiful flowering plants are not only candy to your eyes but they also provide oxygen. If your house doesn't have a place for the gardens(for people living in residential flats) use flower pots to plant flowering plants
2) This advice is for those who have personal computers in their homes and love to download stuffs like movies, games, softwares, etc. While you are downloading data from the internet switch off the monitors. Monitors consume about 80% of the total power consumed by the entire computer( including CPU, keyboard, mouse, ups,etc). I have been doing this and believe me it works.
3) Replace old CRT monitors with LCD screens. CRT monitors consume a lot of power as compared to LCD's. Also radiations from the CRT screen are harmful for the eyes.
4) Use power saver lamps. I have replaced all the traditional; bulbs in my house with with energy saving lamps. Again these power saver lamps save a lot of electricity as compared to the traditional lamps.
5) Don't use shower while bathing; instead use buckets and mugs. This advice may seem unsophisticated, uncivilized and unorthodox but it is true that using buckets and mugs saves a lot of water.