Pondless Backyard Fountain Pond and Waterfall. Even without the fountain, which in Az will grow algae like nobody's business, I think the idea of softening up the patio with a little rock garden with plants mixed in.
Path and steps - I like this idea for an entry to the front door. with a raised planter that recesses to the yard which I would level off completely with the sidewalk. Might work since house is French looking. Lots of work!
Outdoor fireplace, tiered landscaping, and curved path. The raw Copper path lights that will patina over time will look great and unique for years to come. Having the low voltage landscape lighting make these backyard ideas picturesque day and night.