My pup likes to bite my fingers, hand, arm, and toes too- but he has really SHARP puppy teeth and it's broken my skin a couple times. He's not aggressive at all, just super playful but even when I say "no" he thinks I'm playing a game or something and it eggs him on
Anyway, the thing that is a lifesaver for my poor little hands, fingers, and toes is bitter spray! When he gets super excited, I spray some on my hands and after one taste- he learns his lesson. The only
downside is that the bitter spray doesn't last very long. It dries up on my hands so after about 15 minutes, Wall-E is back to biting me! I heard that the squirt bottle thing is really effective though. I haven't tried it yet, but I hear other YT members use this method and its been effective.
Good luck! If there are other useful anti-biting tips, I could use some too!