Because of the rustic construction of the fireplace and mantel, the items that look best as decorative accessories are objects you find in nature. During the spring, create bouquets of wild flowers and place them in a variety of jars along the mantel. In the fall, fill vases with items such as dried pomegranates, mini-pumpkins, decorative objects made from formed twine or acorns. Create a decorative base made from pine boughs and pine cones and decorate it with clusters of red and green apples next to ears of colored corn.
When choosing art and accessories for the wall above the mantel, look for items that fit the folksy/rustic style of the mantel and fireplace. Find a mirror with a heavy oak frame. Stay away from ornately carved mirrors, gravitating instead toward something plainer, such as shaker or mission-style varieties. Choose artwork that features the countryside or a still life of fruit. Add a bit of extra light and color by hanging wrought iron candle sconces. Select candles with colors that contrast with the brick, such as an eggshell or ivory color.
Because the fireplace and mantel have been constructed with such heavy materials, look for decorative items that fit the mantel proportionately. Instead of framing your pictures with thin, aluminum frames, opt instead for some thick wooden varieties. Or collect some large Mason jars and insert your photos inside, facing outward. Line them up according to height. If you're making a candle display for the fireplace, choose fat candles instead of long, tapered candles. To provide a bit of visual interest, alternate the heights and shapes of the candles, mixing cylindrical-shaped candles in with large, ball-shaped candles.
Unusual items on the barn beam mantel immediately catch the eye's attention. Hang a couple of pairs of ice skates from the front of the mantel, hiding the nails under some pine boughs and berries. Show off a collection of vintage wines by creating groupings of three or five on each side of the mantel. Embrace the child within by bringing out your antique tin toys or train set.