The second most important thing is to know how to come to resolution. Resolution is not when someone gives in but when all involved agree on how they will proceed. One way to understand the difference is to know that resolutions are this. Disagreements almost always begin with singular pronouns and past tense verbs. That's an important phase of the disagreement, but it is not a stopping place.
Resolution always comes in plural pronouns and future tense verbs.
Being subject to one another is about learning how to resolve disagreements in such a way that the relationship is stronger afterwards than it was before. That revolutionary thing is what the passage in Ephesians is calling us to do. St. Paul may sound sexist to some and by the standards of this age it is probably so. He was not a sexist in his own day. He was on the cutting edge of the exploration into the meaning of men and women being made in the image of God.