I finally finished shingling the dollhouse and recommend using templates because of the various angles involved. I decided to leave the shingles in their natural color instead of staining them darker, as I felt this would make the dollhouse appear too dark, especially with the dark blue trims. When unsure about shingle color, keeping them natural is usually the best choice. I added a coat of acrylic varnish to enhance their color and grain.
To fill in small gaps around the shingled joints, I used Minwax Stainable Wood Filler, which matches the color of birch veneer shingles perfectly, making it easy to cover any gaps seamlessly.
I also shingled the bay roof using templates like I did for the main roof. I applied clear varnish over these shingles to ensure they matched the others.
You can visit this dollhouse gallery here.