Birdbaths come in a range of shapes and sizes, which matters little to the birds. But ensure that the basin sits on a sturdy base or pedestal that won't tip easily.
Whether you purchase a ready-made birdbath or create one from scratch, choose one with a shallow (2- to 3-inch-deep), sloping basin. A few large stones placed in deeper water serve as island perches for smaller birds.
When repurposing an object for a birdbath, consider its weather resistance and watertightness.
A rough-surface basin, such as one made of concrete or stone, provides birds with sure footing.
Place a bath near a tree for getaways and at least 10 feet away from shrubs and tall perennials to minimize risk of exposure to predators.
Unless you live in a frost-free region, consider adding a heating element designed to keep the water from freezing in a birdbath, or store the birdbath in a protected place over the winter to protect it from freeze-thaw damage.