It is the little things that will reduce environmental impact. If we all start contributing to the effort by changing little things in our habits, then these little things will add up to a large impact avoidance.
There are two things that everyone can do that will hardly impact your daily life. The first is the usage of more efficient light bulbs. Start by replacing all standard and non-dimming light bulbs with compact florescent bulbs. A common complaint about these bulbs is that they give off harsh light. This is a myth. Look at http://www.mcmaster.com/ for a large selection of compact florescent bulbs as well as a color chart you can use to find the light color you prefer.
For lights on dimmers switch to halogen bulbs. These bulbs last longer and use less energy to produce the same number lumen then do conventional incandescents. Again you can purchase these at http://www.mcmaster.com/.
The next habit you can change will actually make your life better. Switch up to use canvas grocery bags instead of paper or plastic one time use bags. How will this make your life better? Do I need to explain that? Well for for the dense ones… Plastic bags rip, hurt your hands, and are small. Paper bags give you paper cuts, are awkward to carry, and rip. You will have none of these problems with canvas bags. Load them up as heavy as you want, then grab the convenient handles to haul them around. Bags can be purchased at http://www.clothing4all.com/ for $3.23 per bag.
Have fun reducing impact!