When I finally started using shrimp to catch catfish -- and it worked real well -- I cut several shrimp in half or thirds, and then threw them into the general area I'd be fishing. Then I threw a shrimp, with a large circle hook threaded through the shrimp, into the area where I threw the pieces of shrimp. I put no other weights or anything on the line. I then put the pole in a pole holder that was stuck in the pond bank. I let it sit until the line really started to zing out.
I believe the tip to use shrimp for catfish originally came from
Shorty and/or Bruce Condello.