I use the A-Z game too although I like to start at a random place in the alphabet rather than at A each time, just to ring the changes. I like to think of landmarks I pass on a journey, towns and villages I've been on holiday or words associated with a them such as the garden or things you'd find in an airport. Never food that makes me hungry! I'm lucky enough to be asleep fairly quickly most nights and if I'm not, at least I'm travelling around interesting places in my mind.