My puppy is ALWAYS in one of the following places:
1. One of her two crates
2. Outside, with me directly supervising, as she plays with my other dogs, or toys
3. Her ex-pen, although she climbs out of that, so now I have to be in the same room and constantly glancing over.
4.Tethered to a safe place (in our case, the fireplace supports), where she has about 30 inches of radius, lots of toys, a soft bed, and NOTHING she can damage (except the bed and the toys). I check on her no less than every 10 minutes or whenever she gets too quiet. (Toys, IMO, should be so interesting that the dog is pouncing on them, pushing them around the floor, chewing them, or 'talking to' them. In other words, you should be aware your dog is playing with them from a room away. If not, then you likely need to invest in different toys. And mix them up. The same old toys get boring day in and day out.)
5. Tethered to me. I attach a leash to her and to my belt. I give her two toys (one chewy and one soft) and she lies next to me while I'm working on the computer, folding laundry, or otherwise, going through the day. She learns to be with me quietly and to move around the house without grabbing whatever happens to be on the floor.
Those are her options. She doesn't play by herself anywhere she wants in the house or outside. When I play with her, I'm either in the yard or she's almost always on the tether so she can't dash off and get into something or potty under the draperies. -- I"ve found that puppies are much quicker than me when I'm sitting on the floor. -- She's very young and not 100% potty trained yet.). A young puppy doesn't need full-run of a house.
Freedom is a privilege. It's earned in very small chunks. When I first brought my pup home, she wasn't potty trained at all, so she didn't even get to be left unattended on a tether at all, or I'd end up with a wet floor or wet dog bed. She's earned being left alone for short period of time. She's earning trust and building up her freedom VERY slowly.
I may sound like a control freak. But I like to look at it this way -- I don't want to put my puppies (or my adult dogs) in situations that they are likely to fail in. Success breeds success. If a dog never learns a bad habit, I don't have to train them to break bad habits. My GSD has only chewed on one thing I didn't want him to chew on (a stuffed animal that had emotional value to me. But it looked like all his other toys.). He's never chewed on shoes, or cords, or pillows or furniture. Am I brilliant trainer? Nah. Is my home impeccably cleaned up at all times? Ha!
I just made sure he didn't get freedom until he earned it.
That, and he burns a ton of energy every day with suitable activities. A GSD that doesn't have a job will make one for himself. Fetch, Walks, Find-it games, be creative and make your own games. Keep his brain and body busy. Give him physical boundaries and let him earn any freedom he gets. THEN you'll have a reliable dog.