Be present with your children; stop thinking in how your life has changed or about that thing that is spinning inside your head that needs to be done. Enjoy the moment and connect with them.
Decide when is the best time to give your undivided attention to your children, 30 minutes per day would be a good start. The connection you create with them when they are young is going to last through out the years. Involve them in the family activities, even the housework, and count on them when you need help; they will feel great. Treat them with respect and fairness. Consider that even before they speak they are already aware of their place in the family.
Be fully present with your children and let your body language express that, let them know they are the reason why you work so hard, why you want to be a better person. Let your face, your gestures and your eyes tell them how proud you are of them and how fortunate you feel because they are your children.
Hug them and kiss them as much as you can, while you can. But most importantly be present and fully engaged so you can be an inspiration to them as they grow up.