Question on patronymic formation
What would be the rules for the formation of a patronymic? I mean, sometimes the name the patronymic derives from remains the same plus the ending, but sometimes there seem to be a change in the spelling altogether — would these be regarded as exceptions or are there phonological / spelling rules for them, too? And would there indeed be such rules that would allow one to make up a patronymic from a given name, or does it take some 'native-like feeling' for such a task?
TIA! :)