Gradually expose shy puppies to new sights, sounds, people and other friendly vaccinated dogs to expand comfort zones.  

Heap treats, toys, pets and verbal praise on your dog whenever they confront something slightly scary to motivate confidence.  

Have your dog repeat doable tasks like sit stays to master skills and experience wins through training.

Display calm assertive energy when introducing your dog to unfamiliar situations so they can rely on your direction.

Avoid overwhelming your dog but regularly bring them along on mild outings like patio dinners to prevent reclusiveness.  

Teach loose leash walking allowing your dog to investigate outdoors under your trusted guidance and supervision.  

Let your shy dog warm up at their own pace, never forcing interactions faster than comfortable. Manage thresholds.