Always Say "I Love You"
Love your children equally, but treat them uniquely. They're individuals.
Say "I love you" whenever you feel it, even if it's 743 times a day. You simply can not spoil a child with too many mushy words of affection and too many smooches. Not possible.
Keep in mind what grandmoms always say. Children are not yours, they are only lent to you for a time. In those fleeting years, do your best to help them grow up to be good people.
Savor the moments. Yes, parenthood is the most exhausting job on the planet. Yes, your house is a mess, the laundry's piled up, and the dog needs to be walked. But your kid just laughed. Enjoy it now -- it will be over far too fast.