What's the best way to find a dead cylinder?

Having rough idling/driving issues. Suspect that the engine (1974 225 bone stock everything) is missing on one cylinder. So what's the best way to determine which cylinder isn't firing? How about pointing one of those fancy temperature guns at the exhaust manifold adjacent to the suspect cylinder while the engine is running. If it's cooler than the rest, this may indicate a dead cylinder. Any other ideas out there? Thanks, all!