Choose a color scheme for the two rooms to share. Choose colors conducive to both relaxing and cooking. For example, pale yellow may increase metabolism and also create a soothing, cheery environment.
Decorate each room with similar appliances. For example, don't decorate your kitchen with stainless steel and your TV room with antique wood. If your kitchen is sleek and modern, the TV room should be, too, complete with glass and steel cabinetry and modular furniture. If you have a country-inspired kitchen with plaid accents, decorate your TV room with cozy, warm flannel and wooden fixtures.
Adorn each room with matching artwork. For example, buy a series of small pieces by the same artist, and hang them throughout the two rooms to create a sense of continuity. Even displaying family photos in matching frames throughout the two rooms fosters a feeling of consistency.