I use a dremmel tool with a sanding attachment to neaten up nails. I think that the method is much better than cutting a nail with clippers. With the dremmel tool, you simply apply the sanding drum to each nail and then go back over the nails again until they are the length that you want them. The trick is to not sand too long on each nail because you are sanding away the nail and the friction of sanding makes it hot against the nail.
I start out by using clippers on the young puppies and then switch to the dremmel tool when the puppies are around 5 months of age. They quickly get used to the sound and feel of the sanding drum. Be sure to wear safety glasses and a grooming shirt because the dust from the nail debris can get into your eyes and will get on your clothes and hair.
Once the nails are done, repeat this about every week until the "quick" has receded and a nice short nail is the result.