I would you clear jars such as Mason Jars and fill them with sand. That would be an easy way to display the sand.
Did you know you can color your sand with food coloring. I did the Mason jar thing, and layered my colored sand. But after each layer I took a crochet hook and dragged some of the color from the first layer into the second layer. and did that for 5 layers.
Fill some pretty jars with sand and seashells, put the lid on tight.
I like that idea. Thank you.
There are some great ideas here: https://www.bigdiyideas.com/44-cool-diy-bookends-easy-make/
I once mixed Elmers glue with sand, enough so it would hold together well. Got a kids beach castle sand mold, sprayed it with Pam, packed in the glue/sand mix. waited until I was SURE it was DRY, unmolded it. It came out with almost all the details. I was happy with it. Just a thought