It is very easy to keep doing the same exercise, albeit unwittingly over and over again. How often does one give a dog a retrieve by throwing a ball or dummy whilst standing next to it? How often have I heard people tell me their dog won't retrieve - look I throw the dummy - see it won't fetch it.
So i thought i might propose, every so often, an exercise. Perhaps a whole routine or perhaps just a part.
To get a dog to return close to you and not run around.
Get hold of a milk crate or similar with a piece of board on the top, or a straw bale or a small low table, tank, teachest etc and get the dog to hop onto it and sit. Much more fun to jump onto something than just come back to you.
Now coming back is a game you can add extras - give the dog something to hold and then call it onto the stand. Retrieving after all is just coming back to you with something in its mouth.
Britmania
I think the secret to good retrieving is to, as you say Guy, make it a game. Pups love to please ,so any means of achieving pleasure for the pup in a game is worthwhile.
I hate to see dogs sent out to retrieve, over and over again with no reward and certainly no pleasure in the dog's body language. If you want robotic type retrieving - get a robot!
We still get our older dogs to play retrieve with toys etc and the emphasis is always on a nice pickup and good delivery.