I use "carpeting" plants in my pots all the time, it keeps my cats from doing dastardly things in the soil!

I use variegated creeping fig in my camphor tree, and it's a nice contrast to the glossy foliage.

I also like: small episcias, creeping jenny/charlie, piggy back plant, button fern, gotu kola (needs high moisture), cascading coleuses, Viola hederacea, spider plant babies (finally, a use for them aside from cat toys!), selaginella mosses, small tropical sedums, and I throw cuttings from many vines like tradescantias and philos in the soil of my larger plants. For larger plants, caladiums, coleuses, and zulu cockspur and other succulent coleuses are nice, plus they're fragrant and they bloom in winter.

HTH,

Celene