Zone 8a Full sun south facing.
Something that has foliage most of the year and isn't boring.

Was considering dwarf magnolia, but I see those want to grow to 20ft around here.
Also thought about some of the juniper varieties.

Just make sure you keep it trimmed.

Southern wax myrtle
Yaupon Holly (Nellie R Stevens or Pride of Houston)

Thank you elcoyote. Those are two excellent suggestions. No thorn bush?

I do really like mock orange, but already have a couple of those

He said he wants something that isn't boring.

Red Tips

I've had red tip photinia, and they do look nice when healthy.
They want to grow 25ft tall, and keeping them trimmed at 7-10ft makes them disease prone (black spot, etc)

I also have 7 or 8 different cypress, 2 kinds. They are sensitive and will die quick on you. In 5 years I have replaced half them .

Yeh, cypress looks incredible for a while, but there's something about the weather and microbe environment here that doesn't agree with them.

Cotton root rot.

Dwarf Silverado Sage

I am onboard with yaupon holly. Great xeriscape plant and can be left bushy or trimmed to be tree like. If you select females they will have the brilliant red berries throughout the fall (just don’t have your car/boat around when the waxwings pass through).Further, as our resident naturalist passes on, the leaves are a source of caffeine in hard times.

I would suggest alternating Silverado Sage and Mexican BoP with Spineless Prickly Pear (yellow flowers) flanked by pods (4-6) Red Yucca and maybe a couple Desert Willows thrown in there for good measure.

North or Variegated Privet - it's a slow grower, but will last a lifetime.