Build and decorate your deck with materials that evoke the simplicity and ruggedness of life out in the country. Skip gleaming, perfectly uniform wood in favor of weathered, reclaimed wood from a barn. Alternatively, paint the brand-new wood with an antiquing stain or a "rubbed" paint effect to make it look worn. Outfit the deck with a table and bench made from split logs.
Select earth tones and colors and patterns traditionally associated with the country in order to make your deck look rustic. For example, rather than painting your new Adirondack chairs a trendy color like bright purple, choose white, hunter green or barn red. The colors and patterns you use for deck furniture and accessories such as sun umbrellas and chair cushions will depend upon what style of rustic decor you prefer -- such as the Victorian cottage look or the Maine farmhouse look.
Outfit your deck with furniture suitable for country life. Not only will this enable you to spend time outdoors eating, reading or just savoring the fresh air in comfort, but also it will contribute to the deck's rustic look. Furniture items you could consider include Adirondack chairs, log tables and benches, gardening benches and flower boxes.
Season your deck with rustic details. Make plaid pillows on your bench seat, choosing fabrics specifically designed for outdoor use so as to maximize their lifespan. Lean an antique pitchfork against the railing. Hang an old galvanized steel bucket from a nail and plant a humble yet pretty flower like bluebells in it.