Balancing the power in any relationship is necessary. But the unfortunate thing is we miss the point. Your relationship with your parents, with your partner, with your friends, and every other relationship requires this balance. It's not like you play in the power position in one role and leave the power on other roles. It will never bring any healthy relationship.
Let's see where should we focus on a relationship to balance the power!
While making a decision, notice if both parties play the same important role. If not raise your voice as per you think both parties need to act on.
When it comes to commitment, time and promises always try to keep balance. If the other side is not responding to the same, you should be concerned about it. And the same for you too.
Time management is a big issue in a relationship, especially in a love relationship. If one party makes themselves available all the time and the other doesn't then there are no balance.
Freedom of choices. Codependency is another thing but freedom of choice should be present in relationships. A person should not always depend on other's opinions.
Response and reaction. If one party shows anger and negative energy all the time and expects the other to adjust then there's no power balance.
There are actually countless points where we need to focus to balance our power in a relationship. But what matters most is a point where both can agree. If this misses out in a relationship it never can work or will never end up good.
We have a misconception that accepting and agreeing can make a relationship better. Well, it may work for some sort of time but after that, a relationship always needs some space, respect, and power to play their role purposefully.