Where to put a menu?

A general, open question for fellow developers. Let’s say my plugin adds a new menu to the administration screen. A number of sub-menus all hang off it with relevant screens attached to them. If, however, I have another screen which is general settings related to the plugin – should I add these as another sub-menu item named “Settings” under my plugin’s menu or should I be putting this screen under the “Settings” menu?

All thoughts appreciated.

David.