1. Structure an App with Classes
Structure a CustomTkinter app with classes, pass data between frames with callbacks, avoid global variables and split the app into several files.
2. Multiple Pages
Switch between multiple pages in CustomTkinter with frames, a navigation sidebar, a back button, a login page before the main app and data shared between pages.
3. Extra Windows with CTkToplevel
Open extra windows in CustomTkinter with CTkToplevel, keep only one window open, bring it to the front, pass data back to the main window and avoid common errors.