Consiglio del giorno che ti può essere utile:
Once a month or so write an email of what they have been doing/accomplishing since you last wrote. Include pictures and videos as well. When they turn 18 or when they graduate high school, give them the password for the account and they have a month by month story of their life along with ALOT of pictures of them growing up.
Also, I have told family about it as well. That way grandparents/great grandparents can have personalized notes for your child too. Personally, I had my grandma write one for my son before she passed, so he will have a note from her even though he was only 1 when she passed away.