Is there anything that reliably finds wooden studs in walls? I've tried a whole range of different stud finders and all of them are at a level of reliability roughly on par with the Psychic Friends Network: "I think there may be something there... or is it over there? No, perhaps there".

In the end the most reliable way of locating studs I found was going outside, measuring the distance between the nails in the exterior cladding, and then using those measurements on the corresponding inside wall.