Puppies go through so much when they are growing, and can go through stages of being afraid of things they weren't afraid of a month ago. They need constant reassurance, and kind firm guidance.
Skipper was no exception. She was great for the bath and drying, but when it came to the clippers on her front legs she really didn't like that, and tried to bite at them. Maybe it was the sound, maybe a past groomer bumped her ankle bones with the clipper blade (something easy to do if you don't have the experience and a light touch). As soon as she showed this reaction I stopped, held her and looked her in the eyes, and gently but firmly told her that that wasn't allowed. Then I reassured her and told her she was a good girl, gave her pets and she was more trusting after that. She also didn't want her face handled, and would try and remove my hands with her front paws over and over. Instead of fighting that losing battle, I took her leash and fashioned a kind of harness like the ones that keep dogs from pulling so that she couldn't lift her front legs up to her face. She was totally comfortable and fine with this, and let me groom her whole face without a wiggle.
There! She learned she can trust me, that I wouldn't hurt her, and that I listen when she says something upsets her. Happy Tails!