Many of the HIs I have stayed at offer a 'pillow menu' that you can select from. The 'boomerang' style pillow I find is helpful to me.

For flying, I have a 'squishy' pillow I take along...I can squeeze it where I need to and it fits in my carry on.

I just took a nearly 6 hour train trip today (figured train was easier then driving - I am flying home). That wasn't horrible but was a little too bumpy for my comfort (plus I have low back/hip problems as well).

Remember to keep hydrated and get up and move around!