I'd do pretty much what has been recommended... Try to isolate the cylinder if you can. If you can't then this is what I did. Of course you don't have to do them in this order. The misfire started about 2-3 months after I repaced the plugs.
Did a compression check- checked good on all cylinders.
Replaced dis cap and rotor-checked for burn marks or arcing on the old one but wasn't sure of condtion so got a quality replacement.
New points- again just wanted to be sure. Got the better ones.
Plug wires- I actually tested the old ones for arcing by misting them with a water bottle at night. You can see the arcing if they're bad. I replaced them anyway because they looked old.
Checked for vacuum leaks and adjusted the carb for to make sure it wasn't too lean.
After all of the above it still would misfire. I put the old plugs in and the misfire stopped. Went and replaced the plugs with a different brand and no more problems. One of the new ones had gone bad...
