Have a running joke you can reference with your kids. Or it might be a silly thing that happened. When you have a rough time, you can break the ice with, "Remember that time when Dad . . ." Laughter has a way of easing tense situations and making things better.
Plan solo time with your kids. (Especially if they have siblings!) They won't have to fight for your attention, and they will feel special when they rejoin the family.
Plan a family outing. Try to find something everyone will enjoy, and insist that everyone attend. Take pictures to put on the fridge. You're building relationships that will last a lifetime.
Not just you, but all of you. Cheer each other on. Have each family member say something good about every other family member, parents included. You will become a tighter team when you do.
Children need your touch. A quick hug, a hand offered, or a kiss on the forehead. They'll remember the touch even when you're gone for the day.