It would be unfair to not credit the creator of the model which Hotaru and Lucy are built upon. The paper modeling master at the now defunct Mizuirogakuen site produced several exquisite models which I built over the past year. Rather than build a new head sculpt from the ground up, i simply took the template for one of his model's heads and adapted it as a blank sculpt. Unfortunately, there were only two suitable candidates:
The Shinku head sculpt, without the extra bits, makes a good base. And the other candidate is Ruri Hoshino, from Martian Successor Nadesico. This one also worked well if you remove the extra hair bits too. I opted for this one as the default template was bigger.
The boxed in components are the necessary parts. I scaled the page to 96% or so to fit the doll. After acquiring the template, I simply placed a Magic the Gathering card underneath the sections and used a stylus to transfer the template. You can use carbon paper if you like, but it's messier. For this, you will need to omit the tabs on every part.
The process of fabricating a head takes a good half a day to complete, for reasons about to be explained. I'll document the exact process used.
1) Transfer the template onto a Magic the Gathering card. Centaur Veteran tends to be a common choice for me to use.
2) I like to use small pieces of masking tape to hold the parts together as I assemble the head. Using small strips of printer paper, I cover all the crevices from the inside. This leaves a smoother outer finish for better appearance. A Magic the Gathering card is stiff, and needs ample time to dry. Two layers is ok, but one layer is sufficient.
Make sure you cut a hole at the bottom of the triangular piece for the neck, if you plan on mounting it on a doll with a ball bearing support neck.
The best way to do it is to build the purple part separately, cut it in half (with the cut going along the join seam), and assemble it to the lower half ofthe face/neck region.
It should look like this. This one was formerly a Glory Seeker.
3) You should sand the outer face smooth, to remove any defects and protrusions caused by shoddy handiwork. My newer method involves taking an array of thin printer paper strips and covering the outer side (the back face in the case of the photo), going perpendicular to the join seams, trying to overlap as little as possible. After that dries, I like to sand the overlaps smooth.
4) Trace over another set of the parts, but this time on printer paper. Use pencil or something light if possible, as it will show up during the painting process. Glue those over the exterior surface now covered by strips of paper. You will now have something close to this:
(Yours will likely look like crap. Don't worry, it happens to all of us. This is my second one, which I never used again. Hotaru is my third attempt, and Lucy is the fifth.)
4) Use this time to draw facial features. Good luck. Drawing on a curve sucks. Be prepared to draw lightly and erase often.
5) If you are satisfied with the appearance, and have sanded the head smooth as you like, you should add the ears now. You can paint now as well.
6) Now, you have the back of the head to complete. You should have a small, quarter sphere piece for the top of the head that may or may not fit. Mine never do, so I solve that problem by enlarging the shell. Make a third purple part template, with cardstock. Assemble that fully.
Place the quarter sphere on the head, then fit the cardstock shell onto that, to complete the sphere. I'll document the hair making process and more of step 6 in the future.