The secret is to not be so obvious. Even people who wouldn’t ever believe in precognition will bust you if they assume you’re acting on nefariously acquired inside information. You can’t warn people that an airplane is going to go down. They’ll look for whatever’s wrong, find it, and think you sabotaged it and then had second thoughts. They won’t even care it’s not possible; anything’s more possible than seeing the future.
Sometimes you just can’t help yourself. I once invited a friend to go to Bermuda with me, just so she wouldn’t go on a Kibbutz and get bombed.