If you regularly use dryer sheets, you might inadvertently causing damage to your dryer.
Take your filter out and run hot water over it. You may be surprised to discover that the water just sets on top, rather than running through. This is often caused by a film that builds up on the mess and causes the heating unit to burn out.

You cannot see the film, but I can assure you, if you use dryer sheets on a regular basis, it's there. The best way to be sure that your dryer is energy efficient and lasts longer is to remove the filter and wash it in hot soapy water with an old toothbrush on a regular basis. (every 3 months).