Commercial fishers are all different, however you can bet one tactict (most of the time) remains the same whichever commercial fishery you are on.
Feed little and often.
Adopt this method and you will keep fish in a feeding frenzy, literally throw in 5-6 grains of corn every few minutes, when you hook into a fish throw in another few grains to keep the fish feeding.
Throughout the day, if bites are getting harder, leave it for 10 minutes before throwing anymore bait in, you may find you have ‘over fed’ the swim, so just wait for the carp to hoover up your left overs.
I often find fisherman caterpulting corn and other bait by the bucket loads, even before they have a rod in the water. This can be disasterouse and wreck the swin for the day. Overfeeding a swim will result in fish pre-ocupied feeding off the offerings you have thrown in, and not taking the hook bait.
This method can be applied to breadflake, maggots, hemp-seed, small chunks of meat, pellets and any other bait that softens up quickly.
In the summer, using this method on a waggler you can see carp in a frenzy just below the surface, as soon as your bait hits the water you can be guaranteed a bite!
Also, feed little and often’ one or two other areas in you swim, if the fish do get spooked you immediately have a group of fish feeding elsewhere. Match fisherman use this approach to ‘bag up’ on a regular basis.
The below books and DVDs provide general advice on commercial fisheries, including where to fish and commercial fishery management.