Couple of the simplest things I have heard
Tell them once make em do it the second time
Don't let a puppy do anything you don't want him to do as an adult dog.
Use a clothes line to make them come.Call them once and then reel them in.Using the clothes line or light cord makes it forget it's tethered
Control/dominate the dog.The worst dogs I have seen are the ones that the owner did not dominate.I had to dominate a couple here and there,and they listened to me more than their owners.
Just roll it on it's back and rub the belly.Especially zee Germans.(hard headed mummssfumms).When they get older,they want to test the "boss" thing out,too
Puppies are easily distracted and bored.So if you have the pup sit and stay,for instance.when you see it start to raise it's butt,release the sit/stay.He did start it,but he will relate it to your releasing him,and the training continues.
Be noisy around him for a while as to ease the pup into shooting and guns.Seems like it's the easiest to mess up for a first time handler.
And slow on the water,unless he loves it already.
Remember classes are more for the human than the dog.The dogs are bread to retrieve and swim.We are the ones who need training.
This stuff can be real easy if you are real consistent.Really

Good luck and have a blast
Oh if you are getting frustrated,lessons are over.
