Talking found sounds for musical purposes:
One of the things I really love about creating "instrument"-sounds from found sounds, is the often complete unique texture of the sounds. You will not find that perfect kick, snare or piano. But you will find something similar, that just adds this extra layer of liveliness to a production.
The easiest way is to take ANY kind of sound, zoom in, select a single sound wave and throw it into a sampler. There you go, free random waveform.