When the pup bites you, your clothing, your hand, anything that you don't want him to bite, grab him roughly by the nape of the neck, and shake him, lifting his feet off the ground. If the pup acts as if it didn't hurt, you didn't do it right. He should react with a yip, and avoid the behavior. If he comes back at you, he thinks you are playing. You have a Dutch Shepherd, not a mini poodle. The corrections need to be VERY FIRM.