The rule of thumb for finishing the interior of a dollhouse is to start with the ceilings first. Ceilings are hard to do because you're working against gravity and all of the paint and glue you will use on it will ultimately end up on your walls and flooring so you don’t want walls and floors to be finished while working on the ceiling.
I used three types of doilies to cover the ceilings. The big round one is for the large rooms and the square ones are for the smaller rooms. The tiny medallions are the center of the big round ones.
First, you have to make sure that your ceilings are completely painted and there are no dark patches. You must paint them thoroughly and evenly, not like if you were just priming them. They might need two coats of paint.
Then I applied glue to the large round doily. I made sure to get all the edges. All you have to do is go around in a circle with the glue, over the outer edges, then the middle and then between the edges and the middle. It doesn’t matter if the glue gets inside the tiny holes, it won't be visible. You can spread glue all over your ceiling instead of putting it on the doily. I decided to put it on the doily because I don’t necessarily want every single area of the doily to lay completely flat on the ceiling because I really like for a lot of texture to be visible. I’m using tacky glue. I suggest that you use the same. Wallpaper mucilage may appear slightly yellowish in the tiny holes of the lace. Tacky glue dries completely clear and its not runny.
You have to make sure you know exactly where you're going to position the doily on the ceiling because once its on, it can't be removed or shifted out of place because the paper is very thin and it will tear easily.
I then cut the edges of the square doily and applied it to all the edges of the ceiling. This hides all of the areas that the round doily did not cover. I then applied a small doily in the center of the large round one. It gives it a thicker, more detailed look as you layer the doilies one on top of the other.
The doilies are very forgiving. They are easily patched and you will never be able to notice where the seams are as long as you put glue on the seam edges and press it against the doily underneath.
For the small rooms, I just centered the square doily and cut the side excess. I have to cut out the staircase opening but I'll do that later.
It's kind of difficult to see the ceiling clearly in the pictures because there's just so much white in the room. I expect for it be much more visible as I add more color around it.