The single best piece of advice I can give you about inspiration is to write it down. As soon as humanly possible. Find a scrap of paper, the back of a receipt, tell Siri to take a note. Just get it done. Because I guarantee you if you don't get it down somewhere YOU WILL FORGET IT. I have lost many an idea that way.
Now, for a random list of things that have inspired me:
- The song Mr. Brightsides by The Killers
- A recycling center
- A mustache drawn on a bus shelter poster
- Mishearing something my son said
- Being trapped in an MRI for 3 hours
- A darkroom
See what I mean? I never saw any of that coming.