In Exeter, I've seen foxes in Pennsylvania, Heavitree, St Davids and in the town centre - all in darkness. I've seen badgers in Pennsylvania as well. Plenty of deer in Stoke Woods. Even more up on Haldon and Telegraph hills. If all else fails, there's always Powderham!
If you can, avoid soap and deodourants for a few days before going out - nocturnal and crepuscular animals tend to have a pretrty good sense of smell. Same goes for your clothing - old, dirty (mud etc rather than oil...), quiet (they've got good hearing too!), comfortable kit. Don't smoke or chew gum. Sit as still as possible. Turn your mobile and MP3 player off so you can hear the animals.
Most of the stand out wildlife shots are the result of many hours of waiting - of course, you CAN get lucky but patience tends to be more reliable than luck.