The two essential ingredients of clicker training, a marvelously effective method of positive reinforcement, are treats and a noise. A clicker is just something that makes a distinctive sound, preferably one that your dog is unlikely to hear in other contexts. While commercial clickers aren’t especially expensive, it's simple enough to make your own. If you are just beginning this sort of training with your dog, practically anything will do. If you started with a commercial clicker, you need something that makes the same sort of sound.
Save a small metal jar lid with a safety button. Safety buttons are the raised areas that pop up when you open the jar so you can be sure the container has not been tampered with. Baby food and pickle jars usually have suitable tops. It needs to be small enough to fit comfortably in the palm of your hand.
Wash any food remnants off the lid and dry it. It’s worth preparing more than one, so you have a spare clicker on hand if the original gets damaged or lost.
Push the safety button out farther with the hammer. Hold the head of the hammer against the underside of the button and hold firmly onto the lid while pushing with the hammer head. The bottom, not the sharp end, of a screwdriver or similar tool also works for this purpose. Enlarging the safety button increases the sound level.
Test your clicker by pressing the button and push it out again until you are getting a loud click. Don’t worry if the lid becomes distorted.
Hold the lid in the palm of your hand with the top side uppermost while training. Push the button with your thumb whenever you need to click.