When retrieve training I only give the pup three retrieves per session and no more than twice a day.therefore the pup won't get bored.also I start in a hall or side entrance of a house,lane etc so the dog has no choice but to pass me with watever it is he's retrieving.it also helps to mix it up from maybe a tennis ball to a half full water bottle or stick to keep it different and eventually when he's doing it perfect a dead rabbit to get him used to mouthing a rabbit.this will all help to prepare him for his first catch.atb