I've been with my spouse since 1999, and I marvel at how quickly time passes while I'm with her. I don't think I've discovered even half of what there is to know about being in a successful relationship with another person, but this is some of what I've learned. In no particular order:
1. Want things. Your spouse can't be part of your life and supporting you if you don't want. They can't go on adventures with you if you don't have a destination.
2. Be responsible for your own happiness. That your spouse makes you happy is excellent, but it should be incidental to seeking the things in life that fulfill you.
3. Go with them. If your spouse wants to travel or seek education, go with them. If they want to take a vacation, make sure you've always got the time and money to be there when they go. You can't be a advocate or protector for your spouse if you aren't there.
4. Be your own person. Having your own friends, books, social network accounts, and so forth is important to having an identity. If you don't know who you are, no one else will either. Do not let the burden of merely being fall to your spouse.
5. Have courage. Things will go wrong, break down and get lost. If you chose well, your spouse will be brave for you, and you can be no less for them.
6. Be a good steward of the little things. If you're the last one up, make the bed. Be ready to do your own laundry, dishes, yard work, and similar. Don't take it for granted that anything collectively held by you and your spouse as stewards is yours or theirs to do alone.
7. Be a good steward of the big things. Avoid financial, legal, and social liability that could adversely influence your relationship. You can't be a good spouse if you are constantly broke, in jail, or so notorious that no one trusts you.
8. Protect them. If someone is kind to your spouse, be kind to them. If someone is unkind or harms your spouse, make sure they feel your wrath. Some preventative overtures may be required, but nothing shuts down problems before they start like others knowing you'll die or kill to protect the one you love.
9. Set and respect boundaries. Some would file this under communication, but not every couple needs to exchange manifestos of intent on a daily basis. They do need to relate to one another what they will and will not do, which requires humility and perspective.
10. Care for yourself. A good spouse wouldn't want to stand by and watch someone destroy you, denigrate you, or damage you in any way. Don't be the villain in this, because you'll put your spouse in a place where they have to fight with you to try and save you. Don't make your spouse compete with an addiction, a preventable health issue, or mental illness because you weren't a good steward of yourself.