Deleting files from deleted Apps

From the time I've had my MacBook Pro, I have always dragged apps I didn't want anymore to the trash and emptied it. But I've read that doing so only deletes the app and that the several files that the app put on your computer when you installed it are still there. I know that there are programs to help you properly uninstall apps, but I have deleted the apps by dragging them to the trash, so I obviously don't have them with me anymore to "uninstall properly". So does anyone know how I can get all these files from apps I have deleted off my computer? I only recently discovered that these remain when you delete an app. Any help would be much appreciated.

Can you tell us which apps you recently deleted by dragging them to the Trash?

If an application has an uninstaller, you should use it and not just drag it to the Trash. Also, there are some complex apps that do not provide an uninstaller but must be uninstalled by following steps provided by the publisher or developer. MS Office 2011 is one such app.

Most other applications can be dragged to the Trash without any ill effect for your Mac. Usually the files that are left behind are small and insignificant.