I too have show cockers and am working on their training at the moment. As they are a little older they are docked which helps.
I am training them using clicker trianing. They are both very fit and are already obedience and agility trained so its progressing well.
I am lucky that I have found someone who trains his springers/retrievers to gun, though I don't think he is 100% convinced show strain cockers will work - a challenge for me!
I have a brilliant retrieve with the younger as we have always played with toys and he has done it from being 4 months old. He is now learning to pick up the scent. The older one we got as a rescue and I have had to teach him to retrieve from scratch - its taken a while but he's nearly there - however when it comes to flushing,no training need as his instinct is so strong.
I would suggest that a major part of the training is obedienced based - the sit and down stays are vital, in fact I have found that once you get the obedience bit correct you can train them to do anything.
The other thing I find imperative is that they watch you all the time. Mine have a "watch mum" signal and they will become oblivious to everything around them.
My only problem is that I have a mega phobia with pheasants so I need seom urgetn training too, I just hate their beedy little eyes, they look evil
If there is anyone in the north doing gundog/working trails with their show cockers I would love to hear from them
Lynn, Forrest and Ash