I agree that consistency is the key!!
That and a crate (in the beginning)
My 6month puppy is mostly trained. I'm so proud of him. The only 2 problems we have right now: him giving me the right message to go outside. I don't exactly know when he does need to go -- he doesn't bark or whine. He's always scratching my feet so can't take that as I-need-to-go-outside. I have a bell hanging on my door, but he doesn't seem to "get it" yet that he needs to ring it if he wants to go outside. So I try to avoid accidents by taking him out every 2-3 hours. Also, he's very distracted outside by many things and people and other dogs. But he's better than he was in the beginning.
Once we get down pat with the pooing and peeing outside, we'll work on him giving me the right message
But for now, I'm happy with his progress!
Good luck with your puppy.. remember patience and consistency is the key.