Q: Separating iMessage due to Divorce

My wife and I recently got divorced.  Many of our email addresses were tied to the Apple devices we shared.  But now that we live separate lives, we need to segregate our iPhones so that we no longer share text messages, etc.  How can I set up my iPhone so that she cannot see my text messages and vice versa?  Right now, I have turned off iMessage, but I am looking for another solution so I can continue to use iMessage.