A student recently suggested "patriarchy" as a writing topic. That's a heavy issue for me to get my mind around, so I tried to think of very specific ways I have been affected by this social scheme. While the differences between the treatment of men and women is enforced in truly frightening ways in some countries today, and while there are evidently still a few matriarchal cultures in existence, here in the US I feel I live in a patriarchal culture that tries to portray itself as egalitarian.
So how has that affected me? I brainstormed. I do think that in one job I was treated differently than a man would have been in terms of mentoring. Also, I took my husband's last name when I married -- though I use my maiden name as my often-included middle name to try to keep it present. I know I've been looked at oddly when alone in some public establishments, where a man, I suspect, wouldn't have been noticed. I'm sure there are lots more, big and small....
Play with this...
If you need to brainstorm at all, take 3-5 minutes to make a quick list of times you feel you were discriminated against because of your gender. Then write continuously for 20 minutes on one of them, describing what happened as a story with beginning, middle and end.
How did it feel to identify and write about this issue? Did you describe a trauma or a mere annoyance? Did writing about it change your mood at all? If the story felt upsetting, try rewriting it with a different (fictional) ending that you prefer. This can often feel empowering.