Respect Each Other
You need to know who your spouse is as an individual and accept that. We aren't meant to change each other. Women often joke about "fixing" their husbands. We shouldn't spend our time looking for faults and trying to improve the other person.
Undoubtedly, we all hope we become better people over time as we get older. We gain life experience, wisdom, and maturity. We improve. Improvement comes intrinsically, though, and not because someone pressured us to change who we are. When you respect each other, it covers so many common problems. Loyalty will be there. Honesty will be there. You will be united. This is part of the foundation because it helps so many other necessary things be built up from it.
I have always loved this quote:
Proverbs 15:1--A soft answer turneth away wrath; but grievous words stir up anger."
There seems to be a focus among parents these days to want to stop yelling at their children. This is a fantastic goal! This goal should be broadened to include your spouse. Speaking quietly and with kindness brings peace to the conversation. I know it isn't easy! We have to discipline ourselves to accomplish this. It is a worthy goal and aspiration. If you can maintain a soft answer, your disagreements (and they will come) will be able to be handled with grace. Read more about positive communication in marriage here.
Be Honest About Finances
Money has long been blamed for problems in marriage. CNBC reported a year ago that "Finances are the leading cause of stress in a relationship..." Money issues are always right up there when people try to pinpoint common reasons for divorce.
Finances is a topic far more complicated than can be discussed in a couple of paragraphs here. Here are some basics. Be honest about your expenditures. Communicate and come to an agreement before making big purchases. A "big purchase" needs to be defined by the two of you and will most likely change as your life changes. When we first got married, anything $20 or more really would have been a big expense for us. The budget was super tight; we were both going to college full time and working part time. Money was scarce. That number has changed for us today--12 years later.
Be open and honest about where money is going and where you want it to be going. Be united on money. I don't think you need to discuss every penny ever spent, but you should both be good stewards over the money you have. Do not go spending it as you desire.
When we were first married and money was very tight, we decided to each have an allowance. Every paycheck, we would each get a set amount of money. That was money we could spend on whatever we wanted individually without stress, but we couldn't go beyond that on frivolous purchases. The budget absolutely didn't allow for it. Read more at Avoiding Debt and Living Within Your Means.
Prayer is a powerful tool. Utilize it.
These are four broad and basic foundational cornerstones to build your marriage on. Do not discount them. They sound simple enough, but when put into practice they help you go higher and reach more.