It's not so difficult to really learn how to distinguish between it's and its. It's just an issue of paying attention and remember a few pieces of information about "it's" and "its".
Let me tell you first a bit about it's. "It's" is a contraction between the neutral second person singular personal pronoun "it" along with the verb "to be" conjugated in the third person singular (he, she, it - is). You use "it's" when reffering to a sentence subject, that is, you just use "it's" as a neutral subj
