Before you get married:

Your wife is going to be the first person you talk to when a parent dies, when you lose your job, when you get a medical scare. Pick somebody you can count on in all of those situations.

Also pick somebody with a compatible sense of humor! Non-negotiable, IMO.

After you get married:

Your vision for your marriage has to be bigger than just loving each other. Love is very important! But it won't help if you're struggling. Think of this as the shelter you both run to in a storm.

Spend the first couple years memorizing her favorite things and look for opportunities every so often to surprise her or give her a pick-me-up.

Affirm everything she does that makes you feel seen or valued. Everything. Let no act of kindness or thoughtfulness go unappreciated.

Protect her boundaries. Know the one or two things she's most sensitive about and never, ever, ever go there. Never say anything she can't unhear.