Baby books are great. All those little handwritten notes about their first words and first tooth and first daycare pals. And of course you include pictures taken during your baby's first haircut or while eating mashed up banana for the first time.
You know what's not great, though? Our inability as parents to follow through and actually fill the damn thing out from year to year. Sure, the first kid might get a mostly complete representation of the first five years of her life. But each subsequent child arrives with a lower and lower likelihood of receiving anything more than a firm reassurance that they were, in fact, babies at one point.
Instead? Email them.
When baby is born, reserve a special email address that you'll use to secretly communicate with them as they grow up. All those sweet things you try to burn into your memory — at a time when you're at your most sleep-deprived — won't be lost forever.
When they smile at you for the first time, email them to tell them what goofy thing you were doing to coax it out of them. When they take their first steps, email them about how they refused to even attempt it until they knew they could walk clear across the room without stumbling. Email them when they hold their arms up to you to ask you to pick them up while saying, "I hold you?" and the cuteness of it almost kills you on the spot.
Email them to tell them how brave they were on their first day of kindergarten. Send a picture of them with their fourth grade BFF and the video where you captured that amazing soccer goal, or their first choir solo. Send them an email each year on their birthday to tell them how they're growing and changing and making you proud.
Then, when they turn 18, give them the password.