golden rule (apart from the GBS one that says there are no golden rules)

Never be without a recording device. Be it audio or PDA or plain old paper and pencil.

I carry a notepad just 2.5 inches by about 4 with elastic retainer loop, and one of those biros that charities give away - flat cardboard stem. Together they take up little room in my bumbag. And it all sits close to my sleeping head too.

Another wheeze if you are desperate is to phone your own answerphone. In my experience the muse strikes when it wants to strike and all you need are the tricks to be known to deal with the situation. The muse will desert you otherwise.

Having said that - the few minutes after waking (even during the night) are the most prolific in dumping ideas into your consciousness. And you can be sure that dreams have put them there in the morning. AND to get those dreams working you do need to feed them with facts, memories, research &/or motivation.

Examples from the arts and the sciences are legion.