The gardenia is an all-time favorite. It's a very fragrant flower and has a nice ivory color.

The hibiscus likes a humid, hot location and it's flowers usually last a day or so.

Another plant to consider is the varigated bougainvillea. When other plants don't have flowers, it gives you foliage and color all the time.

Rosemary is actually an herb used for cooking and for it's scent, but it can be used for a double purpose. It's good for looks and fragrance as well as a cutting herb.

The tropical garden should not require much care once it's established other than watering. There's no need for extensive weeding or pruning and applying a layer of mulch will help retain moisture and keep the weeds to a minimum.