Remember that you didn't marry yourself, you married someone else. Respect that.
Always be as polite to your spouse as you'd be to anyone else. More polite, even.
Thank your spouse all the time for every little thing he or she does, even if it's something you normally wouldn't think to thank a person for, like making the dinner, emptying the trash, being nice to your side of the family, cleaning the furnace filter, etc. Constantly thanking keeps you aware and keeps things in balance. And reminds you to be grateful.
Love means always saying you're sorry.
Remember that however you behave you are giving your spouse implicit permission to behave likewise. That's called the "Goose-Gander Rule."
Remember to treat your spouse as you would like to be treated. That's called "The Golden Rule".
Stretch yourselves for each other. Love is sometimes a matter of the will.
And remember: You will never regret keeping your mouth shut.
Right around the time Tom and I were married there was a quote going around by the Gestalt psychologist Frederick Perls that went:
I do my thing and you do yours. I am not in this world to live up to your expectations, and you are not in this world to live up to mine. You are you and I am I, and if by chance we find each other, then it is beautiful.
At the time the quote was popular I thought it was a bunch of air-headed hippy nonsense.
Now I consider it good advice.