Using this simple technique, you can etch a design into a thin pane of clear plastic sheeting, then enclose the edges of the plastic with reflective tape and embed a battery-powered LED. The resulting design appears backlit and hovering in mid-air, with a laser-like textured glow that photographs cannot do justice to.
Bend the longer (anode, +) leg of the LED to the side at a right angle, just under its plastic dome.
Bend the LED's shorter (cathode, -) leg to the opposite side. Use pliers to put two more sharp right-angle bends in the leg: at 3/8" bend it back down, and at 3/4" bend the leg in underneath the LED.
With the anode of the LED laying across the (+) spring of the battery holder, the LED's cathode leg should point in to the battery holder's (-) pin.
Solder the LED in position, attaching it to the battery holder (+) spring on top and (-) leg underneath. The LED's dome should point straight up and be centered over the round part of the battery holder.