the best thing would probably be to use some vintage items and things from the creepy set, other setless stuff. the other series/sets are either too bright-coloured or too modern imho
i like to try imagining how the room would look being lived in, and breaking it into little areas. at least for actual houses haha, if your house is supposed to be a comercial building or something like that you'd probably rather use another approach!
If you can get your hands on the harvest furniture... I haven't seen a lot of it personally, but what I HAVE seen was purple/black. Might fit in perfectly.