Sorry I've been absent for a bit.
Some ideas for you:
Scent giver such as oil and reeds on a high shelf near front door/parent area
Have dck's plant some scented spring plants near your entrances - can't think of the name of them those purple flowers?
Use colored paper then apply glue in whatever you are learning such as a big letter K then use different things each time to place on the glue such as cotton balls, sand, glitter, pinto beans, etc.