How to reduce energy costs from lighting
Switch it off! The most efficient bulb is one that isn't on - get in the habit of turning bulbs off when you leave a room. The savings do add up.
Do you have the right brightness? A common problem with halogen spotlights is over-brightness - some households simply have more and brighter bulbs than are needed to illuminate an area. This can significantly increase costs if the bulbs in question are 50W halogens rather than efficient LEDs.
Smart bulbs and controls. More and more 'smart' bulbs, that can be controlled remotely are coming on the market. Setting timers or having the option to turn these off if you've gone out and left the lights on by mistake is another useful cost saving strategy.