Adding Custom Layouts in PowerPoint

Kindly note that this works only in the desktop version of PowerPoint and not in the web version.

1. Open a PowerPoint slide in desktop app and go to View -> Slide Master.

2. This would then show the list of layouts present in the slide.

3. Use Insert Layout to add a new layout and use Insert Placeholder to add elements to the layout. 

Alternatively, you can right click an existing layout and duplicate to create a new layout from an existing layout and then edit it.

4. Right click on the newly created layout and click "Rename Layout" and specify a name for your layout.

5. Save your changes. Click Close Master View to close and go back to normal slides view.

All done!