In the diary, like a discussion question or general quandary like what do you do when, or how do you feel about...
Sometimes I get bored and think about what is going on in the world and just create a new thread (not a diary) that has some social relevance and have found that I get to converse more than I do with my diary. I try to challenge myself to create catchy titles, too.
I had trouble grocery shopping and created a thread - Groceries in the time of Covid. I started that What are you Good At thread because I was bored/loney and it's fun, encouraging, etc.
People will engage about relevant, fun, interesting stuff. My life is pretty boring, so I have to use my creativity to figure out what people might talk to me about but I am getting better at figuring it out, over time. It's taken some test runs for me.