(Rather belatedly, but then again, who celebrates it in the daytime?)
We celebrated by going to the pub for the evening and then coming home to light a candle. It's not quite a bonfire, but it's open flame in honor of the day.
C. tells me that parkin and toffee are the foods traditionally eaten on the bonfire days he grew up with. In the process of trying to find out what parkin is, I ran across Preston Gingerbread. I had no idea Preston had its own particular gingerbread. Apparently, it's much like parkin.