If you are using an event marker like a clicker or a short, consistent word like “Yip!” or “Great!” to train your dog, first, yay for you, smarty pants, and second, remember what you’re marking. The information that you are intending to give your dog is that the behavior you just marked is the exact one which is earning the immediately following reward. Basically, just remember to click during the behavior that you want.
For your next training session, pay attention to what/when you click. When training a sit, for instance, did you click while the dog’s butt was hitting the floor or did you click just as she was standing up from the sit? Oops. Even trainers who’ve used clickers for years can forget this and develop a habit of clicking after the desired behavior. Unless he gets too frustrated, your dog will probably still learn what you’re trying to teach, but it’s less confusing for him if you clean up your timing and give him correct information.
If you need to practice your timing, go somewhere with your clicker and without your dog. I like to do stealth practice with human behavior. A busy grocery store parking lot is great for this. I park in a spot with a good view of the customers and choose a behavior to mark, such as “bending to pick up bag from cart.” It’s only the bending that I’m marking, not the picking up. I’m only marking the precise behavior of bending to pick up a bag, not bending to pick up dropped keys. Ah, here is a guy with a loaded cart. Okay . . . click! Aw, missed it. Okay . . . click! Got it! I work with this behavior for a while and then choose another.
Be clear and precise with your information. Your dog will appreciate you for it.