This is the way my Dober-boy and I trim the nails on his front paws.
If you can read snout lips, you’ll understand the muted commentary at the end.
Otherwise, it’s just fun to watch.  Dober chopping is comical.

The board is 13″ by 3′.
The sand paper was from the machine rental dept of Home Depot.
It had a peel off stick backing.  I bought 2 or 3 pieces.