I stumbled upon this blog post today. Its central idea is simple: along with your various digital projects, archive screenshots of them as well. They tend to stay readable even after many years, which is not always true for all digital artifacts.
I have been doing this for a long time, though I have never thought about doing it systematically, so I don't really know how much of my stuff is covered. I just like keeping track; so especially when I made any visual changes to something, I made a set of before/after screenshots. Other things got screenshotted/documented when I'm writing notes or posts about them. But maybe it might be worth doing more consistently.
If you do digital creative work, you probably make things you’re proud of or that you’d like to remember. Screenshots are a great way to do that.