Personally I use snapshots. There is a function to snapshot all selected documents and name the resulting snapshots. (A common name.)
Say you name them “Draft one”, they are then there as a reference, and you work your draft 1 into a draft 2, in the editor. In other words, you saved a milestone version inside your project.
Snapshots can be viewed in the inspector, snapshots tab.
Snapshots are locked in their state and can’t be mistakenly edited. As long as you don’t delete a snapshot, it’ll follow the document it belongs to.
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Alternatively you could duplicate the project. But it is prone to errors. You might at some point lose track and work on the wrong one.
It is not something I would myself do. Though doable.
(I advise against.)
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As an extra to this post, here is a link to my label system that perhaps could be useful to you.
Draft labels.