My idea for keeping a happy marriage. It is not how to fix a broken marriage or how to deal with specific hang ups such as trust issues. It is a very very general idea that I try to live by, and it is very optimistic.
First and foremost. Communication. To make an assumption about the person you love is the first step to dismal failure. Expectations are never helpful and wresting control over any part in a relationship will make the difficult job of sharing a life with someone impossible. Voice your assumptions, explain your expectations and learn that you aren't #1 anymore there's another to think about.
Second. Love language. There's a book that has been quite helpful to me and my interactions with the people I love called "The 5 Love Languages." it maps out the most basic ways that people show love to one another and how they wish to be shown love by others. This ties back with communication but in itself is quite important, especially if you've ever felt starved in a relationship. I won't type it out it's not a difficult read but it is long.
Lastly. Complete and total selflessness. This is the unattainable goal for yourself in your marriage. Think of it as Nirvana to a Buddhist, a constant searching for perfection.
"Love is patient, love is kind. It does not envy, it does not boast, it is not proud. It is not rude, it is not self-seeking, it is not easily angered, it keeps no record of wrongs. Love does not delight in evil but rejoices with the truth. It always protects, always trusts, always hopes, always perseveres. Love never fails." I know it's a Bible verse but it's true and you will find this idea in almost all religious texts.
It's a rosy idea; what I think makes a perfect marriage, and yes it is practically impossible to do in everyday life. It's not about perfection though, since I'm talking about two humans it is redundant to say I'm talking about two flawed people trying to dance their way through life together and try to be happy.
Feel free to harpoon the hell out of my idea, I'm a newly wed, young, with no kids. Both my husband and I come from a families that have 2 unbroken generations of divorces on both sides. My idea came from watching my mom and dad and thinking 'Ok I shouldn't do that." I have no schooling in psychology and I haven't gotten my first degree in college yet.