Business Writing Tips

It’s versus Its

This one is so common, it makes me wonder if anyone actually gets taught the difference between them by any educator they've encountered since Grade 1.
It's is a contraction of "It is". Use it in casual writing; e.g. It's a great day.
Its is a possessive pronoun. Example: The dog is chasing its own tail.
To summarize, it's = it is, whereas its = its.

Business Writing Tips

Your versus You’re

This belongs to the same class of errors as it's versus its: a simple mistaking of a contraction for a possessive pronoun.
"Your" is a possessive pronoun used to indicate ownership; e.g. "When your membership expires, renew it online."
"You're" is a contraction of "You are", used in casual writing; e.g. "When you're finished with your meal, please pay at the counter."
To summarize, you're = you are, whereas your = your.