A minor tip, but a useful one that doesn’t seem to be widely documented/circulated:
Perhaps you might find yourself searching for the customizations or extensions that have been made to a standard object. It usually isn’t difficult to find these manually, but here’s a simple tip to do so quickly:
You’ll notice that you have a “search” option in design view.
If you use c: or e: for the search, it will show you customizations or extensions, respectively.