The main culprits in wood deterioration are sunlight, physical wear and tear, and chemicals. To reduce sunlight, keep drapes and window coverings closed during the brightest times of day, and avoid placing furniture in direct sunlight. It's almost impossible to eliminate all normal wear, but keeping surfaces relatively clutter free, avoiding moisture and spills, and using a protective polish or wax can all lengthen the life of wood pieces. Reducing the use of chemicals such as wine, foods containing vinegar, nail polish remover, glue, etc. around wood surfaces will also help.