Add inexpensive plastic furniture to the outdoor space. Arrange two or three plain white plastic patio chairs around a small plastic table. For added color, throw a tablecloth over the table and place a single brightly colored outdoor pillow onto each chair.
Repair any cracks in a concrete slab or cover a wooden deck with a fresh coat of paint or stain. If the slab or deck is not damaged or worn, power wash the surface to remove any mildew or bird droppings.
Plant flowers around the perimeter of the patio. If there are existing flowers or shrubs, prune them or add a few decorative ornaments, such as a bird bath. Add a few potted plants to the area for a little extra greenery.
Paint a mural onto an outdoor wall. If you are not an artist, ask a friend who is gifted to paint an outdoor scene on an outside wall near the patio, such as a sunset or flowery landscape.
Add outdoor lighting to the patio. That can come in the form of strings of white or colored lights or candles in decorative holders.
Place colorful wicker baskets or an outdoor plastic tote to store toys or decorations. That will keep them conveniently stored when not in use and also protect them from the elements during bad weather.