People seem to have a love affair for apostrophes. If a family’s name ends in a vowel, an apostrophe will surely appear: the Martino’s. There is no such entity as “the Martino,” so no ownership exists. The family is simply the Martinos. Easy.
It’s and its is a constant problem. It’s means it is or it has. That’s it. Its indicates possession: The dog wagged its tail. Also easy.
And there are who’s and whose. The apostrophe tells you who’s means who is. Whose is a pronoun indicating ownership: Whose shoes are these? Ricardo is one of three people whose paintings were accepted for publication. Again, easy.