Wipe any loose clay particles and dirt from the terra cotta pieces with a soft rag. Remove any product stickers and adhesive from the clay surfaces. Sand any rough surface with sandpaper until it is smooth.
Paint a 12-to-14 inch plant pot, a 16-to-20 inch plant pot or urn and the bottom of an 18-to-20 inch waterproof saucer with acrylic or patio paint and brushes on a large, newspaper covered, work surface. Paint the interior and outside of the pots or urn with solid colors. Let dry for at least an hour. Paint a second coat on the pots and saucer bottom to be sure that the surfaces are entirely covered.
Paint decorative images such as flowers, birds or scenery on the painted surface of the pots. Use images that match the decor of your yard. You can keep them simple with subtle color and delicate images such as a series of flowering vines. Let dry thoroughly for at least 24 hours.
Coat the inside and painted exterior of the terra cotta pots and the back of the saucer with a waterproof sealant according to product directions. Set aside to allow the sealant to dry thoroughly. Apply two more coats of sealant for protection against the elements. Do not coat the inside of the saucer as the sealant may be toxic to the birds.
Turn the smallest plant pot upside down and apply waterproof adhesive to the bottom surface. Set the plant pot on the center of the back of the large saucer.
Turn the large plant pot or urn upside down. Apply waterproof adhesive to the rim of the small plant pot and center it on to the bottom of the large container. Allow to dry for 24 to 36 hours.
Set the birdbath up on a patio paver in the yard.