Anchor each end of the fireplace mantel with a tall, standout item. Set a tall wrought-iron or crystal candlestick, depending on the overall room style, at each end. Fill the candlesticks with taper candles in a color, such as red or blue, that coordinate with the room decor. Choose a candle hue to match a holiday, such as orange for Halloween, to create a festive look.
Place an eye-catching decor piece on the small portion of the mantel that wraps around the wall corner and forms the "L" shape. Use the space to display a cherished collection, such as a vintage apothecary jar filled with antique marbles, seashells or sea glass.
Place a centerpiece item in the middle of the mantel. Prop a large, wood- or wrought-iron-framed mirror against the wall to add visual space to a small room. Take a crystal vase filled with fresh, vibrant flowers, such as red roses, yellow tulips or purple hydrangeas, and set it in the center of the mantel as another option.
Surround the mantel centerpiece with smaller decor items. Choose festive pieces, such as mini-pumpkins or small, potted evergreen trees, to give the room a holiday-inspired look. Flank the centerpiece with framed family photos as another option.