Keep the noise out!
(Halifax, Mass. USA)
You mention darkness as one of your insomnia tips, but surprisingly there is no mention of sound in your list.
I am a very light sleeper, and have a terrible time getting to sleep if there is any noise at all. Whether it's the sound of the television from the other room, or even people talking quietly in the next room. Once I get to sleep I'm usually fine, unless there are some sustained louder sounds going on.
So, to get to my tip: Simple, for those people like me -I wear ear plugs if there are any disturbing noises when I go to bed. The soft kind that you squish to put in, they're comfortable and they really help to keep the noise out. I keep a pair handy by the bed just in case I need them, I'd be lost without them at times.
In the spring when it first starts getting warm and it's time to open the windows, I wake like I'm in the middle of the jungle when I hear the birds in the morning! It takes me a couple of weeks to get used to it, again I'd be lost without my plugs during this time.
Your fan tip works great in the summer by the way, I face it away from me unless it's really hot out. The "white" noise it creates puts me right to sleep every time.