I could make the argument controversial, but I could make it that most of the commands we teach pointing dogs aren't absolutely necessary. But there are two you cannot do without: "here" (or "come") and "whoa." Teach those two and every other command builds upon or adds to them.
With them, you have a dog you can hunt with anywhere. Without them, hunting is going to be an exercise in anger management.
"Whoa" isn't hard to teach, and there are a lot of good ways to go about it, but that doesn't stop most people from screwing it up, so here's my strategy.
Before training whoa, your dog should be collar-conditioned if you plan to use one. I do. Put the collar on the dog's neck, even though you won't be using it until later in the process. I start all my dogs on a bench.
Put your dog on the bench. If you want to build a ramp for the little sucker, fine by me. I make mine jump. Get him to stand still until he calms down a bit, then repeat the command "whoa" several times while backing slowly away from him. If he moves, push or lift
him back into place and repeat the command.
At first, you may not be able to let go of him at all he'll want to follow you when you back away. That's OK; just keep at it. He'll get the idea in a day or two. When he does, walk back to him, and if he still hasn't moved, pet him and tell him he's a good boy.
When you can walk away in one direction several feet without his moving, it's time to throw him his first distraction: you're going to walk away in a different direction. His natural reaction will be to turn and follow you, which is exactly what you want. Pick him up, replace him, and repeat the command again. When he'll stay in one place without moving for 30 seconds or so, he's ready for the next step.
Attach him to a lead and keep him at heel. He doesn't need to know the heel command; just keep him snugged up to your side. Walk a few feet, stop, and tell him to whoa. Tell him once. From here on out, you don't need to repeat the command. He'll ignore you, so pick him up and replace him.
SEND A MESSAGE
You can wrap the lead around the dog's waist and tie it off in a loop, which makes a kind of suitcase handle, making him easier to lift. For some reason I've never been able to deduce, dogs that are lifted off their feet get the message more quickly than dog's that are simply dragged or yanked back into position.
Next, instead of stopping immediately after giving the whoa command, keep walking. Your dog's natural impulse will be to follow, so pick him up and replace him. Within a few days, you should be able to walk in front of him, behind him or around him without his moving.
I typically have a couple weeks of training into the dog at this point. I'm a big believer in moving forward in increments that test the dog a little but not too much. Jumping forward too fast is always a mistake. Go slow and let your dog build confidence with each successfully completed command. It'll pay big dividends in everything he does down the road.
Next up is the whoa board. No need to buy anything fancy; a square of scrap plywood roughly 2x3 feet is fine. Have you still got his e-collar attached? Good. Give him a minute or two to examine the board, then lead him onto it. Just before he steps on the board, give him mild and continuous stimulation with the collar, followed by the command "whoa." As soon as all four of his feet are on the board, stop the stimulation.
Here's why this works. Initially, when the dog feels the simulation (keep it mild!) it will confuse him. When the stimulation vanishes (the moment he's standing on the board), he'll soon realize that standing on the board makes the stimulation go away, and before you know it he'll race to the board the minute he hears the whoa command and feels that irritating tingle at his neck. (He may try to run around the board at first, but don't let him.)
Once he's standing on the board, make him stay there for a few seconds while you walk around him. Again you know the drill if he moves even a little, pick him up and replace him.
FREE HIM UP
So, where are we? Your dog has been taught to whoa on the bench and on a lead without stimulation, and on the whoa board with stimulation. He's ready for a bit more freedom. Attach him to a 20' or 30' lead and take him for a walk. Let him range out a bit; no need to keep him at heel now. Give him the whoa command, and if he doesn't obey, give him a mild correction with the collar until he stops.
If you need to pick him up and replace him, by all means do so. Finish this portion of his training by allowing him to run free while dragging the lead. Wait until he makes a cast running from your left to right or vice versa (dogs running toward or away from you are much harder to stop), and give him the whoa command in a clear, authoritative voice.
If he doesn't stop, immediately apply stimulation, then stop it the second he complies. Correct as necessary.
Two or three corrections per session are plenty. More than that and he'll get sticky and won't want to leave your side.
You're just about halfway home. The most important part is yet to come.
From here on out, every time you command your pup to whoa you'll be building on what he's learned. Whether you decide to have a staunch dog, a dog steady to flush, or a completely finished brag dog, he needs to be introduced to birds.
I do this with pigeons, using the whoa board. I put the bird in a simple wire enclosure in front of the whoa board, lead the dog onto the board (upwind or downwind doesn't matter at this point) and tell him to whoa. If he breaks and goes for the bird, I pick him up and replace him the first few times without stimulation, then re-introduce the collar after a couple days.
Eventually, these drills will be followed with similar drills on planted birds. Bring your dog in downwind, and as soon as you see the dog catch the bird's scent and ease into a point, whoa him, then correct him if he disobeys, first by picking him up/replacing him and then, a couple days later, with mild stimulation.
Make sure you walk past him (toward the planted bird) after giving him the command. Walking past a young dog will almost always cause him to follow you and will give you another opportunity for a correction.
He's just about there. You'll want to shoot some penned birds over him, after which he should be ready for his first hunting season. Unfortunately, all the time you've put into him, and all his training, will likely go out the window the first time he gets into real birds.
Don't be discouraged; that's perfectly normal. Leave your gun in the car so you can correct him when he needs it. Do that, and, with an occasional lapse (no dog is perfect for long), he should be good to go for the rest of his life. He won't forget what he's learned.
The training process from start to finish may take a couple months, but it's worth it.
The alternative is to spend your life screaming at a dog who ignores you. I've done it that way and it's not fun. This way is better.