A very productive way to rig a pinfish is through the belly.
Doing this will cause the pinfish to swim erractically drawing much wanted attention from any predator fish in the area.
I have used this technique with much success when fishing potholes on the flats for snook and redfish.
When fishing the potholes, I put a float on and adjust the depth to keep the pinfish just off the bottom.
When doing this insert the hook behind the vital organs (right in front of the anal fin).
The pinfish will not stay alive as long as the other options to rig them but if the hook goes through their vital organs the fish will die very fast.
Be careful of the dorsal fin on top of the pinfish, these can be painful if they stick you.
And make sure to clean the scales off the tip of your hook after the hook is through the body of the pinfish.
If scales are on the tip it can cause you to not hook a fish once you get a bite because the hook may not set properly.