Research desert plants by reading books or going online. Drought-tolerant plants are not limited to cacti and succulents. Desert trees, shrubs, perennials, wildflowers and grasses are also good choices. Decide what types of plants suit your landscaping needs and grow best in your area. Write down the Latin names of the plants so you get exactly what you want. Sometimes different plants are called by the same common name.
Check out your local nursery or garden center. They will likely have or can order a variety of desert plants that will thrive in your area. Before purchasing, read the plant's tag. Make sure it is drought tolerant and thrives in full sun. You can order desert plants by mail either on a nursery's website or through a catalog.
Join the local garden club. Sometimes people in the community have desert plants they would be glad to share, trade or sell. Agaves and some yuccas produce offsets called pups that can easily be dug up and shared. Cacti and succulents can often be propagated from a single paddle or leaf.
Ask permission from local ranchers to dig plants on their property. Often the owners are eager or willing to get rid of cactus plants such as horse crippler (echinocactus texensis) and prickly pear (opuntia humifusa).
Travel to desert regions and visit nurseries or cactus shows in those areas. Cactus shows and sales are held in various parts of the country usually in the spring and summer. For example, in Los Angeles a large sale is held in August. The Austin Cactus and Succulent Society in Austin has a sale every April and September. The Lady Bird Johnson Wildflower Center near Austin also has a native plant sale every year that includes a variety of desert plants.