The secret to having the best relationships is self differentiation. This is a fifty-cent term for knowing who you are, what you like, and having the ability to express this clearly, without hesitation, to another person. It requires insight, emotional intelligence, authenticity, transparency and assertiveness. It is a BIG concept that we can and should strive for throughout life in different circumstances with different people. It is essential for healthy relationships.
I will break it down for you in three simple parts.