Treasure Boxes / Story Sacks / Discovery Boxes are a wonderful yet simple idea that encourage your child to play independently to discover the properties of objects.
Presenting your child with a selection of everyday items from around your house or garden gives them the opportunity to explore using all their senses.
In treasure boxes for babies, I would put a wide range of natural and man-made objects for her to explore. I would make sure I had chosen a variety of different textures, colours, shapes & materials (also make sure to only use non-toxic & items without tiny parts).
For toddlers and older children you may like to theme your boxes, for example based on a book, nursery rhyme or on a particular object. Toddlers like to know the purpose of each item, rather than just what it feels and tastes like!