Perhaps the best approach is one room at a time.First ,pick the spot (or corner) and decide what you want and fill it with all the necessary items.
For example I have a smithy room in one corner of the castle ,I have the soul forge above on the top ,since you can stand under it and it will still work imbuing .Or you can raise it up and cut it up. Because all you need is one tile of it to make it function Then set up smithy forge and anvil .then go about the containers for tool and ore and the deco you want to use .If you want to see I can meet you in game and show you some deco.