Here are some tips of things to include in your letters:

Baby-Toddler:

-When they started crawling & walking

-What words they are saying

-What kind of a sleeper they are

-How they interact with their siblings

-Trips you took that year

-What movies or special toys they are into

-If they had any injuries

-Things they broke in your house

-How much you love them :)

School-Age & Teenager:

-What sports they play

-What hobbies they have

-Trips you took that year

-What do they want to be when they grow up

-Sayings that are popular

-The one gift they want SO bad

-How they interact with their siblings

-Your future hopes and dreams for them