Step 9: Look Into the Downgrade Process
If you run into iOS 9.0.2 problems, you'll want to seek out fixes. But if those don't work, you might want to downgrade to an older version of iOS.
You'll be able to downgrade to an older version of iOS (iOS 9.0.1) but only for a limited time so that's why you'll want to keep an eye on Apple.
Look into the downgrade process right now, before you install iOS 9.0.2. That way, you won't be scrambling if you do run into an issue with the new update.