Replace contemporary or modular furniture with plush, overstuffed furniture. Couches with rounded arms or tables with curved legs, for example, are softer and more inviting than harsh angles. Choose dark or warm wood tones.
Slipcover your furniture so that it matches. Choose solid colors or simple stripes to keep everything uniform and calm -- loud or cluttered patterns make the space less cozy.
Utilize muted, calm colors throughout the space. Earth tones like brown and light green or calming colors like baby blue increase the room's coziness. Use these colors in wall art, on curtains or by painting.
Bring in elements of nature, like framed flowers, sea shells, apples, gourds and wild grass. Decorative items like these embrace the simple elegance of nature and the colors of the season for an all-around calming, natural effect.
Decorate with antique embellishments, like rustic and distressed metal lamps or candle holders. Faux-distressed accessories and authentic antiques give the room a warm, welcoming, lived-in look.