I'm searching for airplane seat cushions.

I was hoping someone on my friend's list has tried a few cushions or has a favorite they'd recommend for long haul air travel? Like 12 hours and more air travel?

Living in Alaska long flights are the norm but I think I have to accept I'm growing older and traveling is painful.

I'd appreciate any and all advice! Sadly getting out of the plane and swimming the rest of the way won't work....