I don't understand your zone.
Where are you?

I have seen a very attractive small hedge done with rosemary in a commercial setting around a coffee cafe here in the Napa valley. Al

92009 looks like zip code for Carlsbad, coastal San Diego.

Petite little shrubs Euyonymous japonicus 'Microphyllus' is quite reliable. Nice that it is a slow grower-less maintenance for you. Boxwood, of course--there are some dwarfy versions, though it gets yellowy at certain times of the year--closer to the coast it is better--how close are you? Common myrtle, Myrtus communis, sweetly fragrant foliage, love that plant. Slow grower, you can keep it that small, and it is extremely tough and drought tolerant. If you are really close to the coast, some of the Hebes make a lovely short hedge, but away from the immediate coast they are not happy.

More informal--Dwarf lavenders are nice--heavenly fragrance--avoid the full-sized ones, they are too big for your purpose.

I have a very short hedge of Iberis Sempervivium.. It is pretty in bloom and looks nice just green. I agree with Hoovb about common myrtle.

There's a "dwarf" common myrtle, and I really love mine. I also grow the Euyonymous, and it has a nice dark green leaf and stays small. The boxwood seems to turn yellow here.
Renee