I find when I get blocked I come to realize that I'm forcing something that's not in my heart. When I write from my heart, it's effortless.
Also, if I am preoccupied with a problem or situation, I can't think of anything else at that time. Or I will write from the pain, not what caused it in real life, but something within that space.
Because I usually share my photography, I get inspiration from looking at my photos.
Very well done and helpful @emmamia.