I totally believe in letting the mood dictate which colors to use. I am very fond of strong blues for a nighttime atmosphere, usually. But when it comes to atmosphere, there are really no rules. Lots of room to play with stuff.
About month ago I have just came back from my modeling contract from Chongqing China. It was really great there. Here you can see some pictures from my job:
Hope you like it :)
When possible (if other stuff in the schedule doesn't get in the way), I try to have decorations up the whole month of October. If not that, then most of the month. Sometimes I will see people putting stuff out slightly before October, and I really admire and envy those people.