Hello Floon, nice to see you followed the Facebook link here okay, then.
As far as moods and writing are concerned, I got used to writing on the train before the day job starts, as well as coffeeshops in the morning/lunch, the Tube home etc, so to be honest, moods don't really come into it.
If you can write with someone jabbing you with an Evening Standard while someone else is thrusting their smelly armpit into your face, you can write to command almost anywhere and in any situation. I don't need soothing music and a nice back massage to get the pen out.
I have a friend who is an army officer and he tells me he can do a similiar thing with his sleep now, and can even catch some Zs in a trench in Kandahar during a half-hour break while being shot at by a sniper.
Strange what you can get used to!