One tip that blogger Scicurious at Neurotic Physiology offers for getting out of academia is to just "get started." By that, she means that if you want to get into, for instance, writing or policy, to find a way to try it out and get experience.
"If you don't start looking and trying, it's easy to remain on the same path in academia, grad school to postdoc, postdoc to another postdoc, just funneling along the path you know," she says. "Get experience elsewhere. Without it, you will not stand out from the herd of other PhDs who are out there looking for a career change."
If you are interested in writing, you could start a blog, or if policy is more your speed, she says to look for a group at your institution to get involved with (and if there isn't, you could start it), and if teaching is what interests you, see if there's a community college or other class that you could teach. There also could be internship or fellowship opportunities to pursue.
At the same time, Scicurious also suggests beefing up your network and polishing your CV for the field you're interested in.