Most folks don't really pay too much attention on lighting since they think that your lights are not taking in a lot of energy. Light bulbs can have a huge effect on your monthly bills because they can consume plenty of energy if they are used often. If you have been using incandescent bulbs, substitute them with CFL or LED bulbs immediately.
There are some people who do not actually care about the lighting since they firmly believe that the bulbs are not taking in a lot of energy. In case you are always making use of your lights 24/7, you can expect that they could greatly affect your regular bills. If you are currently using incandescent bulbs, you should replace them with LED bulbs or CFL.
The simplest approach to conserve energy is to make of all-natural lighting throughout the day instead of making use of your artificial lighting. You can your artificial lighting at night, but make sure that you allow the all-natural light enter your house in daytime.