I don’t believe in a visible treat pouch. With some dogs, I’ve seen the pouch become a distraction. For awhile I tried hanging the pouch from my belt on the back of my pants, but I found that location to be inaccessible. So instead, I carry treats in a sandwich bag in my pocket. I’ll palm a pile of reserve treats in my left hand, the same hand I carry my clicker in. My right hand is always empty unless it has a single treat to be immediately given as a reward.
During training, I feel the dog needs to be focused on me. I want him or her making and holding eye contact with me. Some dogs will begin to focus more on the treat pouch or on the treating hand than on you. That’s why I hide the pouch and shuffle treats from left to right as I use them.