My first post in Writer's Journey talked about where I got the idea for my hero of my book. He's single handedly inspired me to create the world he lives in. In my bio, I talk about recurrences that happen. A lot of self-help teachers call these inspirations, nuggets of gold, moments of genius. Over the twenty or so years, bits and pieces of ideas have come and gone, all pertaining to this particular story. Then someone in my imagination said, "This would be cool for your story." I might need to seek some help.
I've mentally collected different nuggets of gold and stored them in my noggin. When I got serious and decided to write this book, I bought a tiny notebook and wrote down every single nugget of inspiration. To my surprise, I've used most of them. About a quarter of the ideas I threw out. That's fine. Better to have more than you need.
When I read or hear other artists talk about where they get their ideas, a lot of them use this method of collecting, writing them down. JK Rowling did this. I saw a special on her where she would write on napkins, cards, anything that would take ink. I think if I tried to write this story early on in my life, I may not have had the opportunity to gather the ideas that I need.
Get a notebook. For me ideas come when I do the most mundane things. I'll be walking and all of a sudden, pop. An idea.
A word of caution. These ideas are fleeting. There have been a number of times when I'm taking a shower, I get an idea, I take a moment to remember it, and poof. It's gone. Take the time to write these golden nuggets down. It's these gold pieces of ideas that may change your writing, project, life.