Instead of free feeding, feed your dog at set meal times. Most adult dogs do well with two meals a day, but puppies need more frequent meals. Stick to a high-quality, dry dog food and keep your dog's meal times as close to the same times each day as possible. Give them access to food for about 20 to 30 minutes at each meal. Remember to walk them after they eat!
Take your dog outside to eliminate as often as possible, and reward it whenever it eliminates outside.
If you are considering a young puppy, remember that they need to eliminate every hour. Regardless of your walk schedule always take your new dog outside after playing, napping and about 20 minutes after eating. Try to use the same spot each time. Keep walks brief, and encourage your dog to sniff (this is an important part of the canine elimination sequence). Praise the dog as soon as it begins to squat and as it eliminates. Do not play or take long walks with the dog until after it has eliminated outside.
Pay attention to your dog's body language when inside.
Behaviors such as pacing, whining, circling, excessive sniffing or squatting indicate that the dog may need to eliminate. If you catch your dog exhibiting any of these behaviors, interrupt the dog and immediately take it outside. If it eliminates outside, praise it profusely.
Catch it in the act!
If, and only if, you catch your dog eliminating in the house can you correct it. The correct must take place at the same time as the undesirable action (preferably as the act begins). The most effective correction is to startle the dog with an unpleasant stimulus (a loud noise, squirt of water, etc.) as soon as it begins the unwanted behavior. You can then redirect its behavior. This means that after interrupting it, you should immediately take it outside to eliminate. Praise it if it goes outside. Remember to always use the weakest stimulus possible to interrupt your dog. Your goal is not to scare the dog, but to startle it.
Punishment has no role in house-training and can actually intensify the dog's undesirable behaviors. Dogs make immediate associations.