You can undo most of what you did yo something you draw or paint with a digital device so experimenting with new creating ideas on work you are doing has no cost because you can always go back to a previous version. It might be fun to have a similar option when you are drawing in the real analog world and not on a digital device.
A transparent “paper” that behaves like real paper, so it reacts to your drawing and painting utensils (pencils, pastels, etc.) in a similar way to real paper. You can then have new layers of this “paper” added to your work and experiment. If you don’t like the result, just through away the top layer(s) of this “paper.”