Mine in full sun does better than partial shade, much thicker. I pair it with yellow foliage.

Or silver.

Can you give me the names of the silver and yellow plants that recommend please?

A few --

Silver - lamb's ears, any of them

Yellow --
Yellow sedges, Luzulas; grasses; bulbs (daffs, crocus)
Iris pallida "aureomarginata'

Also consider reds & oranges & greens.

Bottom line: You gotta go to local garden centers, if only to look! (I dare you to come home empty handed.)

Yes, the easiest way to come up with plant combinations is to compare what's in stock at local garden centers. Of course, if something is in bloom there at a different time than it will bloom in your garden that could complicate things, if you match it up with other items and then it doesn't correspond with them the following year. With some common, short-lived flowerings, like those of rhododendrons you need exact timing to catch the peak bloom

With evergreen foliage you don't have this limitation, of course.

Looks nice paired with variegated japanese sedge or planted with succulents, sedum "Cape Blanco" would make a nice contrast. Sempervivums or echeverias also look good with black mondo grass in containers but echeverias would need winter protection in our neck of the woods. Black Mondo Grass IS a very slow grower, I have a fairly large clump of it now but it took years. Chlorophytum comosum variegata is said to be hardy here, but I've never tested it...yet :).

Annette

I appreciate the names of plants, it helps me research their properties before I go to the nursery. Also, to check if they are deer resistent. Thanks all.

I have it with Sedum 'Lemon Ball', a golden thyme whose name escapes me and with Sagina subulata 'Aurea' all in full sun.

It is one of the slowest growing plants at our place. Here's what I do to encourage the best growth -- give it what it prefers moist soil in part to full sun. Mulch 2x a year with compost & water during dry spells. Leave the flowers & seeds to self sow though I've not seen seedlings probably because of the mulch I add.

Earlier this year we moved golden creeping Jenny, Lysimachia nummularia �Aurea� under & around the Black Mondo for contrast. I plan to keep an eye on it to make sure the grass isn't over run with it. I thought about the golden lamium, but decided on the lowest growing plant.