Sounds super cheesy, but my husband and I before bed every night, ask each other what the other is thankful for, that happend that day, or in general. It puts perspective on the fact that things could always be worse and that we have it pretty good, even when sometimes things are stressful, and seem impossible.
I also make it a point everyday, to say "I love you", and to thank him for everything that he does. Like when he takes the trash out, I tell him immediatly thank you for doing that, I really appreciate it. That makes him in a better mood because I recognized what he does, and then in turn he does the same.
Let the little things go, and pick your battles. When he does something to irritate you, think to yourself is it really that big of deal? Or am I just upset or stressed about something else?
Always, always be honest with each other.
Remember to laugh at the things you cant control.
Have fun and remember to take it easy and make time for quality time together. Live, love and laugh.