This costume hood can be any LED-eyed creature you choose just by changing the colors. This circuit uses one simple, close-range RF remote to control two receivers on the same frequency, and Arduino code employing interrupts to achieve responsive animation changes. Full tutorial on Instructables.
Magnetic circuit with bluetooth app controlled LED strip under my Vespa scooter creates ground effect lighting/underglow. Full tutorial on Instructables.
This is a list of my favorite LED diffusion ideas, which I hope will provide you with some sparks of inspiration for creating your own next-level illumination.
Create a fun light-up flower using 3D printing and Tinkercad! Optionally add some needle felting to diffuse the light from the LED at the center of the flower. The special Glow circuit assembly in Tinkercad makes it easy to put an LED and battery circuit into your 3D prints.