Problem with moss or flowers is you might tear it up with use of any furniture or heavy traffic.
BUT, you could do spreading flowers such as flocks (phlocks?) or other low lying herbs/flowers.
I guess Moss would be fun to "make"
I found a moss recipe if you care to call it home grown
Moss (i'm guessing from a riverbed or woods?)
50% curdled buttermilk
50% stale beer (for me this is hard to allow to happen)
Blend until it's a workable liquid, and cover soil with mixture by pouring/sprinkling between patio stones.
Keep watering frequently.
expect results similar to growing new grass from seed, it may take a full year to fill in completely so be ready to deal with wet dirt.
Check this out