With a 12-week-old puppy, I always take mine out after they eat, and encourage them to walk around. Then as soon as they potty I take them back in after lots of praise. When they nap, they go out as soon as they wake up, and after a good round of play, they go out. Other than that, I try to take them out every 30 minutes or so, and I keep them close beside me so if they start to sniff and walk around, I can pick them up and head outside with them. I always say "outside" when I open the door, and when they are a little bigger and walk to the door, when they come back in I give them a tiny pinch of a treat as soon as we walk back inside. I keep a special bag of treats right by the door that are only used as potty treats. My 7-month-old goes to work with us every day, and he still occasionally has an accident if I fail to offer him the opportunity to go outside, but now they are very rare. It is much harder if you are gone and your pup is left home alone a lot. Then it is necessary to crate them and make sure you come home as often as possible to let them out. Hope this helps!