Shoe growth chart! Perfectly acceptable to lose one shoe from a pair, since you only need 1 for this project... Shadowbox, Kids Shoes, Cute Ideas, Growing Up, Growth Charts, Shadows Boxes, Old Shoes, Girls Shoes, Baby Shoes
Growth Chart! $35 - fabric growth chart (do one for each kid and give to them when they grow up)
oversize ruler growth chart- vinyl decal. perfect first birthday present- you supply the board.
i like the split pins (or even nails) and swing tags to mark height. Write date & age on swing tag.