When we plan our meals we should try to eat organic foods. This is because organic food doesn't produce green house gases while being produced and even the waste matter of organic food like various pulps and seeds are source of food for other organic things like animals and other plants. If we consume junk food we are adding wastes that are not bio-degradable and consuming resources used to make those junk foods. Moreover there is little nutritional benefit in junk food; it's not good for you! Organic food helps you lead a lot healthier life with far fewer medical bills.
Also, buying foods that are individually packaged are not only a waste of resources, but in energy to produce, refine and package those items. Instead of buying juice boxes, buy bottles and a large bottle of juice, or even better; powdered concentrate and make it yourself! Buy in bulk and in large sizes. Most people can afford the small amount of extra space this requires. This will decrease the amount of stuff going into our landfills. Doing this will help to not over use resources and make this planet a more efficient place.
One of the biggest polluter to the environment is the cars. Vehicles have become such an important part of our lifestyle that we have completely forgotten the very purpose for which the things were created and we have become addicted to using fossil fuel consuming vehicles; Sports cars and SUVs and Trucks that you don't actually need! These will cost a fortune in gas and emit more pollution just to satisfy our lust for power and luxury. We should walk when possible or bicycle for a short distance. Also take public transport when going to work. All of these things will significantly reduce the green house gases and we will leave a healthier environment for our next generation.
Conserve water. This is the easiest one to do. First, turn off the water when you are not immediately using it (ie: don't leave it on while you brush your teeth). We have all developed the bad habit of letting the faucet run while wait for the shower to warm up, or while wait for a cold glass of water. Second, fix leaky faucets. Even a small leak can use 10 gallons of water a day. We only have a small amount of water on this planet. What would happen if one day your faucet just didn't put out water? You can survive in the dessert for days or weeks without food, but not more than 4 days without water. If it's that important, let's protect it and let it last.