So, it seems that every 6 months or so, my neck requires me to change pillows. A few years ago I started waking up with a raging literal pain in the neck, which persisted until I stopped using my beloved soft, squishy feather pillow. Desperate, I decided finally -- after going through a few other feather pillows of varying squishyness -- to get a contoured Memory Foam pillow.
This worked out great for a while and the pain stopped! But after some time passed, I guess I fell back into the wrong sleeping position so it started to be mildly painful again. I found that turning the contour around, and sleeping with my neck on the big bump, fixed it again for a while.
Eventually though, even this failed me. So I bought a Sobakawa Cloud Pillow. Wow, neck pain stopped again. Bought a 2nd one, even! Love it. Well, after several months, once again, my neck decides it doesn't care for the pattern I've begun comfortably sleeping in. Doh!
So I switch back to the contoured memory foam. The cheaper knock-off brand, even. Neck? Yep, it's happy.
I guess the secret is just whatever it takes to keep your neck in the proper position all night long. For me, it seems to involve preventing the neck from crunching up at the bottom edge of the pillow, through whatever means.