Some people like to give their dogs really long, but creative, names. While these names are cute and creative, they will often lead to a nickname that the dog will learn rather than the long name. The nickname may ruin the affect of the long name so it might not be a good idea to give the dog a huge name.
The country of origin for the animal or animal's breed can be helpful for naming a pet. If your pet happens to have been native to Ireland, giving the dog an Irish name can be a good idea. The same goes for animals from Germany, France, and Scotland. The same principle can be applied to an animal from anywhere.
Personality can be a huge key for a pet's name. For this reason, waiting a few days to name the pet is never a bad idea. Also, animals grow. Naming a kitten "Kitten" is cute and makes sense until the kitten grows up.