I was advised it is easiest to use a file on a newborn. I got one of those big black ones that looks like it has black sand on it. When the baby is tiny, I use that. Then when they get bigger, I use baby nail clippers, but only if they are perfectly still. I really take my time lining it all up. dd1 I had to do it while she slept. dd2 wakes up if I try that, so i have to do it while she is awake. i ask her if she is ready for me to do a manicure, ready for me to trim her nails, and though she is not verbal yet, she understands everything we say.
I put her in my lap, her back to my front, so it is like trimming my own nails she has a hard time staying still, so it takes a while.
I also resort to fine tuning with my mouth and teeth while we are nursing. This is due to laziness on my part I am sure... If I feel a snag on a nail, I do what i would do on my own nail, I bite it off, (very gently) to even. Once dd1 was about 4 yo she started trimming her own nails...
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