How do successful freelance writers brainstorm?

[Gaia]

Lately, I've been having trouble coming up with story ideas and want to know how my fellow freelance writers come up with theirs.

I live in a relatively large city and was writing for an entertainment magazine. The other writers use the same web site I use which lists upcoming events, so I find it difficult to come up with ideas because they're often taken.

The editor for the magazine I've written for the most said as far as new ideas, "If it's an event, that's fine, but really I'm looking for trend, issue-based or news story topics that might add some heft to our entertainment coverage."

Thank you all for any pointers in advance!