Glass jars or clear containers with wide mouths (including lids)
Favorite toys or brightly colored fabrics
Place a toy in each jar or container and screw the lid on just a turn. Show your child how to unscrew the lid to get the toy out. As he or she gets better at unscrewing the lid you can screw it more and more.
M* had a good time with this but this but all the while I sat there thinking, do I really want her to know how to get into jars? Hmm....