I love doing my Shaker Cards with foam.
I first cut the foam and some Plastics twice in the size I wanted it do be.
My 2nd step was to die-cut the star (I cut both pieces at once to make sure that the star matches
Apply the plastic with the adhesive of your choice to the form. In case you use glue as I did make sure to give it enough time to dry.
Now you can fill one of the stars with glitter, sequins ...
make sure that it fits to the depth of your star or you won´t be able to shake
Glue both pieces to together and start decorating the card