In our work in creating workflows for Switch, Rods and Cones uses private data to a great extent. And in many cases, what we're doing is we're creating private data keys as early and as often as possible. And they're so simple to use.

Setting private data is something you can do with any folder location. It's one of the many things that's an option in the folder, set job private data. What you've got here is multi-line text with variables.
Here are the data keys, so I'm setting the job key, job number, and the key, customer name. And then you can set a variable into here. In this case, I'm using the split part one and the split part two from StringSplitter.

But I don't want to have to remember four flows later, what was split part one again? So I immediately take this data and convert it into named variables that make sense. Here's my job number. Here's my customer name.

I always name my variables in exactly the same way. Because of my consistency, it makes it easier and easier for me to remember how to use my variables and recall what the variable names were later on when I use that data.