If you have a young one, you know that sometimes they need a little light in the dark night.  When I was a kid, I had a glow worm that I loved, so I decided to make a glow-in-the-dark lamp for my little one.  This design can also be used with non-glow filaments as an upwards-facing LED lamp shade using colored filament.  The design is easy to modify in Fusion360 for free if you want to change the base size, height, or other design elements.

The key modifiers to play with are user parameters shown here:

My defaults are for a base with a 110 mm hole in the bottom and a 12 mm thick “foot” for the shade.

I include two different styles here to pick from:

1.  Solid style, suitable for vase-mode printing.  This uses less filament and is single-wall thick at whatever thickness you want (my example file here is 0.6 mm wall for a 0.4 mm nozzle).  This is probably best for colored filaments. 
2.  A Thick style:  For glow in the dark filament you need more material to get a good glow than you will get with the spiral vase, in my experience. This thicker style has a minimum wall thickness of ~0.8 mm, but the thickness of the model varies over the height to create “light and dark” spots which invert in brightness when the lights go out when using a glow filament.  This is what is pictured in the photos, where you can see the contrast from the light and dark sections.