Though typically interior designers recommend against investing in trends, mirrors are one trend that you can safely invest in without fear of it going out of style. However, as with any trend, there are certain guidelines you should adhere to. For example, avoid trendy finishes on the mirror, such as etching or embedded trim, as these can date the mirror and look them out of style. Remember, however, that your frames can easily be swapped out as your style of home decor changes and you can find frames in traditional, contemporary or modern styles.