1Ride the Wave
Once you've found a sound you'd like to sample, pump it through an oscilloscope emulator for visualization (I like Soundcard Scope).
2A Clean Slate
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).
3Carve it Out
If you put your mind to it, you can make a lot of different cards.
4To the Third Dimension
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?