Once you've found a sound you'd like to sample, pump it through an oscilloscope emulator for visualization (I like Soundcard Scope).

LABO treats each waveform it reads as a periodic wave, so your waveform needs to remain roughly unchanged between periods.

A "blank waveform card" template (.SVG) is provided with Waveform Card Pack 1 (see download section).
Use this to carve out the shape of your chosen wave (Inkscape is my vector graphics editor of choice).

Using boolean operations, remove negative space until you're left with a positive "top" to your waveform card.

If you put your mind to it, you can make a lot of different cards.

Import that SVG and extrude it to a 3D shape! Export it as an STL, slice it up, then print it out!

What was that noise?