A super simple light pipe to give visibility to the Pi Zero's onboard LED. This modification allows you to easily see whether or not the Pi is powered on, without having to wire in an LED.
Simply drill a pilot hole through the post just above the D-pad, break off the post with a pair of needle nose pliers, then drill the hole from the top with a 3mm bit. Use a dab of superglue to attach the light pipe, making sure it's pointing to the right.
I printed with 2 perimeters, 0 infill, 0 bottom layers, 2 top layers. It might work with more standard settings, but the more plastic between you and the LED, the dimmer it will be.