"When can I stop giving my dog treats?"
This is probably one of the top 3 questions I get asked as a dog trainer, and I totally get it! Having to remember to bring treats and tangible reinforcers like toys when we first start training our dogs can be a lot of extra work for us. It's one extra thing to add to our to do list in an already too-busy world, one more thing to have to think about. And we've heard for SO LONG that our dogs should just 'do it for us', right? So when can we fade the food and move to just reinforcing using a few pats on the head and a "good boy!"
Well, I have some bad news. But I also have some good news!
Bad news is: unless you have a unicorn dog that will work for strictly praise and pets (they are out there, but they are FAR rarer than we have been led to believe), you should really never stop using food or toy reinforcers in your training. The truth of the matter is that when we are out in the real world with our dogs there are SO MANY other reinforcers in the environment; there are squirrels, and smells, and other dogs, and people. And if we want certain behaviors in the presence of these competing motivators (because that's really what 'distractions' are, just something that the dog may want as much as or more than what you have to offer), we have to make sure that what we are offering is something that the dog finds MOTIVATING. If you have nothing to offer but some praise and a scratch behind the ear, typically the environment will win, and your dog will learn than you don't have anything of real value to offer to them anymore! Behavior is LAWFUL, and while it is rare to be able to make any guarantees when it comes to behavior, there is one guarantee in the world of behavior: if you stop reinforcing a behavior with something the dog is actually WILLING TO WORK FOR, something that motivates the dog, that behavior will extinguish. Say buh-bye to all of that hard work and training you have put in. (Exhibit A of Regis being distracted by the environment below!)

Now of course you could say "well, just put the behavior on an intermittent schedule of reinforcement" (trainer speak for don't reinforce every response, reinforce every few responses), and yes, that is true! But you still have to reinforce the behavior SOME of the time and since we're not training service animals or bomb sniffing dogs that HAVE to respond under certain conditions lest something terrible happen, I would much rather we OVER pay our dogs. We humans are, unfortunately, quite good at being stingy, so let's try our best make sure we are doing our part and reinforcing our dogs for choices we would like to see more of.
Now for the good news: most dogs will happily work for easily prepared pre-packaged snacks (see my recommendations here). With all of the varied options on the pet market today it doesn't get much easier finding "to go" reinforcers for our dogs, and getting your dog's 'stuff' together doesn't have to be a logistical nightmare every day if you set yourself up for success. Think about what you ALWAYS leave the house with when you walk your dog. Any responsible dog owner I know doesn't leave the house without poop bags, yes? Or without their dog on their leash? Make the treats live with these unforgettable things! If you always have a bag of treats binder clipped to your leash, or if you keep your poop bags in your treat pouch like I do, you will by default remember your treats since you have to grab those other items too! (Fun fact: I totally stole this tip from a "good housekeeping" article to help people remember to bring their lunches to work! Keep your car keys with your lunch box= keep your poop bags with your treats!)