There are lots of plants. There are tons of cycads. Hibisicus would make great tropical flowers and philodendrons would be great for foliage. Bamboo is another great plant, some are very cold tolerant. There really are tons of plants to grow in your climate. Lots of types of palms would thrive. Also tree ferns would be nice in shade. Plumerias are great for sun. Cannas are quick to add color. Bromelaids look nice mounted on trees or planted in light soil in the ground, maybe even a pot. Cacti can look pretty tropical in some instances. Chinese ground orchids are one of several that can grow in the ground, but there are many you can mount on trees. As for trees, citrus are great. Ficus are also nice. magnolias are perfect for some situations and some are cold tolerant. And what cal yard doesnt have a birds of paradise!
Hopefully this can get you started!
A tropical landscape should have lots of tropical looking plants of different heights and colors all planted near each other. A water feature such as a pond or pool would be nice too!