One strategic way to mix and match your furnishings is through use of color. It's a great way to provide continuity in a room with pieces of different styles. For example, you may be a flea market hound who owns a room full of mismatched wood furniture. So consider painting it all one color. A monochromatic scheme of white walls and painted white furniture in a variety of styles is the basis of the popular Shabby Chic decorating style, which has been in vogue for years.
Complementary colors lie across from each other on the color wheel and provide the most vibrant color combos, so don't be afraid to make bold choices. But if you want to use multiple colors in your furniture or accessories, consider a neutral backdrop, such as white or beige walls and trim.