In PowerPoint, when you’re in the Slide Sorter or Outline views, you can press Ctrl+D to insert a slide in your presentation that’s a duplicate of the current slide.
This doesn’t work in edit mode, unfortunately; for that, you need to use the Insert menu’s Duplicate Slide command. (Get there simply by pressing Alt+I, D).
Such kind of shortcut techniques are really very fruitful for the users to access the keyboard in an efficient manner all the users must use all kind of necessary shortcut technique that will be really very fruitful for them. It also helps them to save time as well as make a grip on the keyboard as well. They should be thankful for all these fruitful tricks.