Well, of course, tails can be tucked out of the way, and I would imagine that it would be particularly untroublesome on soft surfaces such as a couch. As differently as anthro-people would sit from cats and dogs, I would imagine that the tail would still be able to wrap around the side of one's legs in a similar way, and maybe it would be easier, as there would be more muscle to sit on which could elevate the tail root. Also, I would imagine that it would be possible to kind of sit on your tail, with it coming out near your legs, if you wanted to recline (even if you got a numb tail and had to shift a bit every now and then
)
The one thing I see being a problem though are toilets... Current modern ones are really un-tailfriendly.