To ourselves generally since we would be walking around the house and doing stuff. If we sat down to watch TV, I'd tuck the end of the leash into my pocket or something so I'd have 2 hands free but could still easily control the dog if needed.

We got a slip-style leash that was easy to throw over his head for this purpose, but you could also use your dog's regular leash connected to their collar. Ours was about 4-5 feet in length so he could never go very far or get tangled up around furniture.

One thing that was really great about the leash was practicing the right behavior when he is called. He used to just run in a diagonal like and jump over furniture to get to us because he was so over-eager to do anything. We practiced with one of us calling "Come!" and the other leading him at a jog around furniture. Now he knows that's how he should come to us if we call him from a distance.