Using an e-collar there are very few "methods" one can really use. The dog either turns it off or avoids it. It's pretty simple.
There's a lot more to a hunting test or field trial dog and if there's one thing I've noticed about Fred, it's that he's constantly trying to invent efficient ways to train on his own. Training with a group, while necessary and fun, is the least efficient dog training one will ever do. If you're trying to run a business it can be downright troublesome to sit in a gun station for three hours a day in order to run your dog for 10 minutes. As much as you want to be social and help everyone out, the time just isn't there. Unless you have a trailer load and some good helpers, training retrievers is incredibly time consuming and inefficient relative to other things.
I can do 4-5 dogs in basic obedience at my home in the time it takes to drive, set up, run one dog and take it down.
My guess is that Fred's bigger problem with creating a FT or HT dog isn't his lack of skills but more likely a lack of time.