As I begin coding, I start with the V1 working script and make a copy of it (save as whatever_V2)

I also add to the top comments what I am implementing, sort of a checklist. Rather than erase the comment, I simply change "implementing" to "implemented".

This helps tell future forgetful me what present forgetful me was intending.

I have some scripts in double digit versions, but I always know where I was in the development process.

I do something similar with all of the spreadsheets that hold the game history as well. There is the current spreadsheet, and there are also older versions that were analyzing one thing or another. The master data is actually stored in CSV files so they can be easily transferred into any new sheets AND read by Python scripts.

Also, I back up everything. Once at the end of every coding session, including draw history updates, to a second internal hard drive, and separately on a monthly basis to a thumb drive.

Before I started up again, I did go through the painful process of losing everything when the old laptop died. Mostly power ball stuff and a ton of Vtrac sheets.

The version control is super important because you always have a working version of a script as you try to implement new features.

Another way to do this is with free version control software like git, but for the simplicity of what I do, that seems like overkill.