Keep your refrigerator no higher than 40 degrees and the freezer at 0 degrees.  Clean your refrigerator every 1-3 months with a mixture of 1 Tbl. Of baking soda dissolved in a quart of water.  Wipe down every inch of your refrigerator with this solution.  Make sure all hot foods have cooled before refrigerating them.  This prevents the hot containers from warming up your refrigerator.