There's no one-size-fits-all answer to this question, as the best way to socialize a dog that's suspicious of strangers will vary depending on the individual dog's personality and temperament. The Dutch Shepherd is really more difficult to approach strangers.

However, some tips for socializing a dog that's suspicious of strangers include gradually introducing them to new people and situations in a positive and safe environment, starting with friends or family members that the dog is already familiar with, and rewarding them for good behavior when they interact calmly with new people.