I've made my best notes sitting outside cafes on busy streets, or in murky bars in foreign cities. I sorted out a big series of problems in the novel I'm just finishing while sitting drinking a long line of solitary beers in a bar in a small coastal town. The hangover was pretty brutal, but I'm not sure I'd have found the solutions any other way. Part of the job of being a writer is learning how your head works - when to push it, when to step back. This kind of self-management is actually far harder, I think, than learning how to write decent prose.