I think you are asking for an example custom window that’s tied into the menus? That’s a great point. I should have included that.

SnapSettings is a good example I found in decompiled Unity code: https://github.com/MattRix/UnityDecompiled/blob/cc432a3de42b53920d5d5dae85968ff993f4ec0e/UnityEditor/UnityEditor/SnapSettings.cs

Snap Settings are in the Edit menu and they allow individuals to configure the X, Y, and Z units that the transform position handles snap to when moving.

This is a cool example because it contains a custom window GUI, it’s tied into the menu system, and it even includes most of the logic needed for snapping. The OnGUI callback draws the GUI using GUILayout and EditorGUILayout calls (which is a whole other topic), Line 84 uses the MenuItem attribute I wrote about to show the window from the Edit menu, and static members store the snapping information so it can be referenced in Handles https://github.com/MattRix/UnityDecompiled/blob/cc432a3de42b53920d5d5dae85968ff993f4ec0e/UnityEditor/UnityEditor/Handles.cs

Hope that helps, and thanks for the feedback. Maybe I’ll write up a tutorial on making custom editor windows some day.