Here's a little peek into my foley process.
Whenever I discover an interesting sound, I record as many variations as possible.
Then cut them up and sometimes tweak them a little before they go into my library, so they may come in handy during future sound-design and music projects.
This is a nice lazer-like "pzieuww" I accidentally triggered when I was replacing the nylon strings on my guitar with steel strings.
Final Cut Pro