You don’t need a clicker for this exercise. Stand near your dog in a low-distraction environment. Say “Watch out!” and toss one treat on the floor, about 1-2 feet to the left or right of your dog. When the treat leaves your hand, continue pointing your finger towards the spot (but remain standing) to help your dog locate the treat. Repeat this step 10 times, randomly over the course of a day and when your dog least expects it.
The order is important so be sure you are NOT saying “Watch out” at the same time or after you toss a treat. Always say the cue before your toss the treat. You need to have a solid conditioned (automatic) response in order to move forward.