You can find my music here:
I record everything with the internal mic of a MacBook Pro and sequence with Garage Band.
The samples are really labor intensive. I use Audacity. I record something and figure out its pitch. I’ll get as many different pitches as I can out of a given object. Then I make tons of pitch-shifted files, until I have one file for each note in about four scales. I save these in their own folder.
Then I pick a sound effect software instrument in Garage Band and turn on musical typing. I drag each file I recorded to its corresponding key and then save the new instrument.
After all that, I can select the instrument and play it with my midi keyboard controller.
There’s gotta be a faster, easier way, but I don’t know of a cheaper one.