I have created a full calendar page, showing their baby pictures, calendar with the year and day they were born. This is my first page. After that I have sections of all their firsts and the day and year they happened.
You can go with a garden theme for summer and make tiny little flowers out of beads and sticker felt paper. Take a piece of white card stock and cut out the shape of a window and place in a picture you like , then take a bouquet of flowers and place them along the window for a whimsical theme.