It's fun to make a themed night light in any style you choose.
You will need:

A cardboard craft box approx 5x5 or smaller
Plastic window (can be table cover cut to shape)
Hot glue
Paper cutouts (mermaid, treasure chest, or any other design)
Craft sea grass, shells
Paper flowers
Pompom ribbon
Acrylic paint
Sparkle paper
LED night light
jute ribbon

For each night light it is the cutting and gluing of all the parts that can be tricky. The easy part is embellishing in your own style.
I will post a tutorial on how to attach the plastic window and the LED light and how to create depth for the paper cutouts inside and how to affix everything so that it does not fall apart.
These night lights handled carefully will last forever.
You can make them as simple or as elaborate as you choose and have fun with any theme!