I'm almost done with my first halo helmet but I have a small head and I don't think a motorcycle helmet visor will fit my helmet. So are there any other methods out there?
Motorcycle visors come in a variety of sizes, including ones for children - if your helmet is small, there's still a viable size option for you. Otherwise, I would echo peterthethinker and suggest attempting a home-made vacuum-formed helmet visor.
It's a flexible material that works great as a visor. It is comparable to 110lb cardstock, so it bends and flexes very well. The tint is great too, even with a flash on you can't see the persons face underneath.