These are some of my favorite design elements to warm up rooms during the winter months. They are also great year-round when the proper materials, textures and colors are used.
1) Panel Draperies. The addition of panels drapes to large windows creates a wonderful ambiance. Whether you use them to frame, for softness, or for full function, fabric panels dress a window like no other treatment.They can add opulence to a casual room and warm a minimalist space. Fabric options are nearly endless and the header style - pleats, grommets, tabs, etc. - can easily accent your style.
2) Plants: Even if you don't have a green thumb you can bring greenery into your spaces. My favorite plants are flowering orchids whose care is as simple as a placing in bright light and monthly watering. They are inexpensive but elegant and gorgeous. Philodendrons are a very easy care plant; check with your local big box store or nursery for a variety that suits your home. Dried arrangements work well, and some faux plants ARE beautiful.
3) Hurricanes. One of the most versatile accessories is a glass hurricane lamp. They have so many uses; they're not just for candles and not only for traditional spaces...although that is their most oft-used style. Despite the cold weather, a shell-filled hurricane on the table is refreshing. I often add gold and silver balls to mine and use them in the bathroom, porch and kitchen for a wonderful ambiance. Coastal and cottage style homes can use this idea year-round.
4) Books: While I love open space on tables, books add a lived in feel, an architectural element, and sophistication to consoles, end tables and coffee tables. Placing them underneath the tops is both practical and attractive; they can be read but don't clutter the surface. For a clean look, cover unattractive but often read books with decorative wrapping paper, interesting wallpaper, or simple brown or white papers; use what suits your style!
5) Rugs: Area rugs instantly warm up a room define the space. They add visual interest, scale, pattern and texture to any room. There are a variety of materials, but get the BEST you can afford since you want durability as well as aesthetics. For neutral style add a solid color rug with texture.
2) Plants: Even if you don't have a green thumb you can bring greenery into your spaces. My favorite plants are flowering orchids whose care is as simple as a placing in bright light and monthly watering. They are inexpensive but elegant and gorgeous. Philodendrons are a very easy care plant; check with your local big box store or nursery for a variety that suits your home. Dried arrangements work well, and some faux plants ARE beautiful. 
5) Rugs: Area rugs instantly warm up a room define the space. They add visual interest, scale, pattern and texture to any room. There are a variety of materials, but get the BEST you can afford since you want durability as well as aesthetics. For neutral style add a solid color rug with texture.