This is an extension to the following question:
None of the answers go into how to properly write your extension so that it releases when ArcMap exits. I'm positive it's somewhere in ESRI's help, but I haven't been able to find a complete example.
In my extension am I looking for all created objects and then making them null when they're not used anymore? For the extension specifically, am I listening for ArcMap to close then making the extension null? I'm not sure how to do that from inside the extension, or where it should be done from outside the extension. I can post code if that would be helpful, but would rather get a pointer to the How-To, then I can post code if I can't get it to work.