Omega oils help, I've started taking one every morning, 1000, you can get them in most health food shops. It might just be the placebo affect, but it does seem to keep me a bit clearer.

Somebody mentioned a while back that vitamin C supplements made them a bit hyper, and I was surprised, looking back at my online tracker, that it seems to have the same effect on me. So it might be an idea to take some vit C on mornings when you're cloudy, but not to take it at night time.

Hope that helps.