Applying concrete stains to existing concrete makes any slab look new. Begin by cleaning the patio concrete thoroughly. If the concrete has endured years of abuse, look for darker stains to hide the bad patches. Concrete stains come in a wide variety of colors ranging from blue to tan. Many stains are made from hydrochloric acid and acid-soluble metallic salts mixed with water. The acids react with the lime in the concrete and permanently change the color. Read stain manufacturer's instructions carefully or risk living with something worse than you have.
Use your existing concrete patio as a foundation for a paving project. Though time consuming, laying brick or pavers with mortar gives a professional result that lasts for decades. Traditional clay bricks will transform a mundane patio into an elegant space. Clean the existing concrete, lay standard mortar about one inch thick and lay the bricks (or pavers) in a pattern in the mortar. Allow 1/2-inch to one-inch wide spaces between the bricks. Make sure to add mortar carefully to the ends and joints to avoid air pockets.
Group three or four large planters filled with colorful annuals in a corner of the patio to draw interest. Look around for things you already have that may give your old concrete patio a new look. Investing in a new patio table, chairs and umbrella also help any boring outdoor area. Outdoor area rugs are another inexpensive solution. Forget the fake grass rugs of years ago---modern outdoor rugs have pretty patterns and better durability to endure a season or two. Get creative and soon your patio will feel like another room in your home.