Amelia, I have a running list of topics I add to whenever an idea pops into my head. I’ve found it’s vital to capture these when they appear — otherwise they’ll disappear. I’ll use paper, a digital notepad, or my memory if the other two aren’t available.
I’ll spend a lot of time now the day before thinking and musing about my topic. By the next morning, I’m raring to write.
There’s no magic to this. It’s all habit. The more you do it, the better you’ll get. You’re going to be thinking about something all day long anyway. Why not let your thoughts drift to what you’ll write and how you’ll connect dots for people?