Moss lawns are very tranquil and serene, I personally love them! From my own
experience, the biggest is part making sure that they do not get killed by a layer of fall leaves. Moss is not vigorous and has no vascular structure, so it can't really compete with a layer of leaf litter by growing through. Raking will tear up huge sheets of moss if you're not careful, so I generally like to resort to using a blower of some kind but even that can blow sheets of moss away if you're not careful. It's definitely possible just needs some caution. Moss doesn't anchor to the ground very strongly, as the rhizoids are not as strong as
roots, and they thrive in unfavorable conditions to most other plants so the lawn can be a bit fragile at times.
That being said the idea Joylynn is an excellent idea and probably your best bet. Mike and Timothy covered the conditions of moss pretty well, essentially a compacted, shady, and acidic soil. Although I have heard that some sun tolerant moss prefer more alkaline conditions. If the conditions are not favorable, there are also other low-growing groundcovers that may serve a similar purpose.
I hope this helps,
Eric S.