I went to the JH Audio recommended audiologist to get impressions done for my JH-16s.
Sound idEars, Hearing and Speech Therapy
750 West Broadway Avenue, Suite 1212
Vancouver, BC V5Z 1J2
The receptionist told me it wasn't going to be the actual audiologist doing it, but someone else who usually does impressions (there was term for her, but I forget now). I said as long as she's the one who was recommended by JH Audio, then that's great. It was only $50, and she was very nice. They used the cotton dams as recommended, and she had me do an open mouth impression. There wasn't a bite block, but that didn't seem to be a big deal. At the end she asked me to open and close my mouth a couple times (I imagine to loosen the impressions).
I've gotten my JH16s back, and the right one is a 100% perfect fit and let left one is probably 90%. It's so close that I probably won't bother sending it back. If my ears are wet from getting out of the shower, and I'm walking it makes a popping suction sound. This mostly goes away when my ear is completely dry, though I still get it a little bit. She also told me if I needed new impressions for a refit, it would be free. I'd definitely recommend them for Vancouver (a couple other places were $100).