There are many ways to prepare for marriage, legally and non-legally. 

Some things one can do to prepare for marriage: 

  1. Change "me" to "we"
  2. Take premarital classes or a course
  3. Attend couples counseling with a licensed therapist
  4. Start adjusting and planning your finances, or speak with a financial advisor
  5. Talk about children or the lack of children
  6. Practice communication styles, such as the Four Horsemen of Communication
  7. Keep an open mind about the expectations of marriage
  8. Discuss boundaries about wants and needs
  9. Build your friendship as friends and as partners

Some things one can do to prepare for marriage on the legal side of things: