Organizing your custom message templates is easy!
FROM THE WEB APP
Step 1: Go to Settings > Custom Templates
Step 2: Click the message handles to drag & drop the order of your messages.
Step 3: Use the "Internal Display Name" to differentiate.
Step 4: Done
FROM THE MOBILE APP
While you can send messages using templates from the mobile app, you can only edit the custom templates on the web app at this time.