Making long flights tolerable. What do you do?

I suspect that all of us above a certain height find long flights to be quite uncomfortable. Do you have any tricks or tips on what you do to improve the situation?

For me:

• Pay extra for the extra leg room seats (if available)

However, I'm usually stuck in an aisle seat. For resting, since we are too tall to really rest our heads anywhere, I bring an inflatable device that I can put on the tray table and then lean forward onto.