1.Make sure there is nothing you would not want your mother or the insurance company lawyer to see.
2.Search your name to see that what comes up is acceptable. Make whatever adjustments are necessary.
3.Check your privacy settings.
4.Don't answer emails or requests from people you don't know. (Keep in mind that because of the lawsuit process, the opposing legal team knows a lot about you and could send you an email that might make you think you know each other.)
5.Don’t accept a Facebook friend that you don’t know. Set up your Facebook to require an email before you will accept a new friend.
And, speaking as a lawyer who knows that most lawyers are way behind the technology curve, volunteer to your lawyer if you are prominent on Facebook, Twitter, or other social media. It could make the difference between a salvageable case and getting blindsided at trial.