Start with a shell of your choice and push it into the sand face down.
Use an old frame to also push into the sand.
Carefully remove both pieces.
Fill the hole with Plaster of Paris.
Continue to fill it all in.
This is what it will look like.
Let it dry in the sun while you go swimming.
An hour or so later, gently pull it out of the sand and rinse it in the water. And now you have a mold of your favorite shell to remember your favorite vacation.
I will be linking to these parties!